Taking a look at Orange. The color focuses on time, but also focuses on survival, and takes place in the ruins. Unity is a logical theme in the color, as it suggests insular groups surviving for long periods of time in harsh environments. Here's a card meant to suggest all these things mechanically:
Ritual of the Eons5O
Sorcery (M)
Convoke
Take an additional turn after this one. You can't draw cards during this extra turn.
Mechanically, slow and steady seems like the right pace for orange, and gradual effects that trigger once-a-turn could be a heavy theme. Some cards/effects that I could see moving to orange would be Paradox Haze, Disowned Ancestor, Instill Energy, and Puppeteer. I also see it having some synergy with artifacts, particularly with regards to the graveyard (scrapping and scrounging). Argivian Restoration, Treasure Hunter, and Kuldotha Forgemaster abilities could be orange as well. As the slow and steady color, defender synergy also makes sense. As scrappy, tough underdogs, orange mages probably also have at least some access to weenie creatures. Above all, it's the color of incremental advantage. Orange creatures tend to have higher toughness than power. Mix and match these abilities, and you have a full color. It's closer to white than any other, but it is definitely not white.
Orange creature types include things like insects, scorpions, elementals, birds, lizards, beasts, skeletons, humans, goblins, kobolds, hounds, cats, rats, and other survivors. Maybe elves could be there, since they traditionally live very long lives. Classes would largely be shamans, warriors, and scouts.
Ruinseeker1O
Creature- Human Artificer (C) T, Sacrifice an artifact: Add one mana of any color. "The ancients built many useless things, and I know just how to use them."
1/3
Infninite Patience4O
Enchantment (R)
Whenever a source would deal damage to you, prevent all but 3 of that damage.
At the beginning of your upkeep, choose one-
-Each player sacrifices an enchantment or land.
-Draw 2 cards then discard 2 cards.
Obstinate Frillback1O
Creature- Lizard (C)
Vigilance, trample The kobolds eventually abandoned that particular hill.
2/2
Orange Shard1
Artifact (C) 1,T: Add one mana of any color. 3O, T: Untap target permanent.
Kobold Rallymates3O
Creature- Kobold Warrior (U)
Other Kobolds you control get +1/+0.
At the beginning of your upkeep, create a 0/1 orange Kobold creature token.
2/3
Ancient Timeteller O
Creature- Elf Shaman (C)
Sacrifice Ancient Timeteller: Target player takes an additional upkeep step during their next turn. (The additional upkeep follows the normal upkeep.) "I have lived five human lifetimes, and remember all of it." - Sakui of the Dead Bird clan
1/1
Crossbow Tower3O
Creature- Wall Archer (C)
Defender 1,T: Crossbow Tower deals 1 damage to target creature. The goblins hate the kobolds, the kobolds hate the humans, the humans hate everybody, and they all love the towers.
3/3
Three-Legged Sphinx3OO
Creature- Sphinx (U)
Flying
At the beginning of your upkeep, draw a card, then discard a card. Half blind, mostly toothless, and missing a leg. Still even large predators leave her alone.
1/5
So, as other people have said, the idea of making this many new colors is mind-boggling. I think if you view this as an alternate to the color pie, rather than an addition to it, it becomes more reasonable to think about. Especially considering that the color pie has pretty much claimed all the territory there is to claim.
Just using the stuff that you laid out, I'll make a couple little designs to test the waters.
Containing two cards and a colorshift for each color.
P= Purple
Scuttling Quartzic 2P
Creature- Crystal Scout (C)
As long as Scuttling Quartzic is untapped, spells and abilities that target it cost an additional 3.
3/2
Quartzic Pother P
Creature- Crystal Rogue
When Quartzic Pother deals combat damage to a player, you may sacrifice it. If you do, that player discards a cards.
1/1
Foolish Cowardice P
Enchantment- Aura
Enchant Creature
Enchanted creature is a Coward in addition to other creature types.
Cowards can't attack.
Purple does seem to work, and I think Cavern as the land lends something nice to it. It represents a human sort of dishonesty, but also has an instinctive feel. Mechanically, it is hard to bring this out of Dimir's wheelhouse. The logical abilities are protective keywords, evasion, card advantage, and hand disruption, all of which are decidedly Dimir. However, I could see things like Enchantment/ Aura synergy being present here (as a representation of mental tampering).
L = Yellow
Infinitude of Thought 2L
Enchantment- Aura (U)
Enchant Creature
Enchanted creature can't attack or block, and has "2L, T: Draw a card."
This shares a lot of space with Beige. Because of the desert subtype, Desert doesn't work as this color's land. This is going to share some space with Abzan. Landfall makes sense here, as well as other land-based strategies. It isn't that hard to design for this color mechanically, but the flavor is often going to end up being dull.
O= Orange
Ruins of Old Baloura
Land- Ruins (R)
(T: Add O.)
Ruins of Old Baloura enters the battlefield tapped.
When a spell or ability controlled by an opponent destroys a creature you control, you may create a 1/1 orange Survivor creature token if you control no other creatures.
Kobold Crewmaster XO
Creature- Kobold Soldier (R)
When Kobold Crewmaster enters the battlefield, create X 0/1 orange Kobold creature tokens.
Other Kobold creatures get +1/+0.
1/1
Blast 1O
Instant
Destroy target artifact or enchantment.
Ruins are a perfect land for this. This color feels very red/white. Besides being tough and doing red things, though, there's not that much to design for this color. Perhaps artifact synergy should be placed here.
E= Brown
Eaten By Ants 3E
Sorcery (U)
Destroy target creature. Each player creates 2 1/1 brown Insect creature tokens.
Hungering Deepkin 4E
Creature- Beast (C)
Bloodshed- When this creature kills another creature in combat, or deals combat damage to a player, put a +1/+1 counter on it.
4/5
Fall Below 1E
Instant
Target creature gets -3/-3 until end of turn.
Yes, brown is very green. Mechanically, I think it will feel very green/black, and won't be that hard to design for. There are always baddies in the woods. Unlike green, this doesn't feel like the ramp color. Perhaps that's more yellow. This color will be creature focused, but looks like it could be a solid removal color.
K= Pink
Shared Prayers 3K
Instant (C)
Equality 1K (If you cast this card for its Equality cost, it affects each player instead of just you.)
You draw two cards.
Doddering Elf K
Creature- Elf
Remain (You may choose not to untap Doddering elf during your untap step). 2: Tap or untap Doddering Elf.
As long as Doddering elf is tapped, all creatures get +0/+1.
1/1
Soul Singer K
Creature- Human Cleric (C)
Whenever another creature enters the battlefield, you gain 1 life.
1/1
This color feels shallow. It's too nice and happy all the time. Perhaps nationalism and blind loyalty should be added to its characteristics. Right now, there's not much to do with this outside of white, and group-hug abilities. It would make sense if this were also a color for aggressive zealots who will do anything good or bad for their beliefs. But again, all that kinda just seems like white. Perhaps if the color were mechanically tied to something major, it would help. For example, it would be interesting to make this a graveyard color. It may not seem obvious with pink, but it could also be the color of ancestors, heritage, and history. There isn't a clear graveyard color among these, so it's a logical fit. I could also see Silver, Yellow, Brown, and Beige working with the graveyard in various ways. I also think that "Village" would be a better land for this color than "City".
D= Gold
Ignoble Sellsword D
Creature- Human Mercenary Warrior (U)
First Strike 3: Put a price counter on Ignoble Sellwsord, and gain control of it. Any opponent may activate this ability if they pay an additional 1 for each price counter on Ignoble Sellsword.
3/2
Lothrid's Coffers3
Artifact (U)
1D: Add 1 to your Wealth.
You may spend Wealth instead of D mana.
Ruthless Dracobaron 4DD
Creature- Dragon
Flying
Whenever you sacrifice a creature, target opponent sacrifices a creature.
4/4
This color feels like one of the easiest to design for mechanically. You have shifting loyalties to work with, resource management (a decent color for ramp), aggro potential, and so on. There's a lot money can buy, and there are a lot of mechanical options here.
I= Beige
Distant Eye I
Creature- Eye (U)
Flying 1: Distant Eye gets +1/+0 until end of turn. You may look at target player's hand.
-3/1
Esoteric Puzzle2
Artifact T: Add P, O, L, E, K, D, I, N, V, or S.
III, T: Create a 5/1 beige Horror creature token. Exile it at the beginning of the next end step. (It doesn't have haste)
Observer of the Strange 1I
Creature- Human Wizard
When Observer of the Strange dies, draw a card.
1/1
This treads the line between blue and eldrazi (colorless). It's not that hard to design for mechanically, as you can always throw your leftover designs to the weirdo.
N= Turquoise
Mad Sharkfolk 2N
Creature- Fish Shaman (U)
When Mad Sharkfolk Attacks, discard a card.
Bloodshed- When this creature kills another creature in combat, or deals combat damage to a player, draw 2 cards.
3/3
Inspired Frenzy N
Enchantment- Aura
Enchant Creature
Enchanted creature has haste, and attacks each turn if able.
When enchanted creature attacks, spells its controller controls cost 1 or N less to cast until end of turn.
Tempest of the Mind 1N
Sorcery
As an additional cost to cast this spell, discard two cards.
Draw three cards.
This falls right into the red/blue zone. Mechanically, it's not hard to design for, but it feels like anything I can come up with is either a red or blue ability.
V= Silver
Wry Arcanist 1V
Creature- Human Wizard (U)
Instant and sorcery cards you own are arcane.
8V: Return target instant or sorcery card from your graveyard to your hand.
1/2
Shrill Cantor V
Creature- Human Cleric (R)
Spells cost your opponents 1 more to cast during your turn.
Spells cost you 1 less to cast during your opponents' turns.
0/1
Questing Arcanist 2V
Creature — Human Wizard
When ~ enters the battlefield, you may search your library for an instant or sorcery card with converted mana cost 2 or less, reveal it, put it into your hand, then shuffle your library.
1/1
Wizards and clerics. This feels like it will be easy to design for conceptually, but a little tougher mechanically. It is an interesting mix of Izzet and Orzhov. I find this color interesting.
S= Grey (instead of silver for some reason)
Weeping Mummer S
Creature- Elf Clown (C) T, Exert Weeping Mummer: Lands and creatures enter the battlefield tapped this turn.
1/1
Mournfulness S
Instant (C)
Target creature doesn't untap during its controller's next untap step. Draw a card.
Muffle 1S
Instant
Counter target spell unless its controller pays 3.
This one is tough. Who wants a whole color based on melancholy? Nevertheless, it lends plenty of design space, it's just not going to produce cards that are fun to play against. I instantly got the image of these weird, sad, black-and-white clown people, sort of like the opposite of the cult of Rakdos. There'll end up being plenty to work with here. The lands can't be tundras though. Tundra is a card.
Absolutely, my feeling is that THIS WORKS!! But, it only works as an alternate color pie. All of the concepts you've explored are placeable within the existing color pie. Obviously, Wizards is never ever ever going to do anything like this, but that shouldn't stop you. I think a set using these as the colors could be made, and could be really cool.
The main thing is that every player needs to have easy access to "add one mana of any color" effects. The inherent cost for adding multiple types of mana is less here, so I think you could and should have something like this at common:
Ruined Promenade
Land
Ruined Promenade enters the battlefield tapped. T: Add O or L. 2,T: Add one mana of any color.
Ritual of the Eons 5O
Sorcery (M)
Convoke
Take an additional turn after this one. You can't draw cards during this extra turn.
Mechanically, slow and steady seems like the right pace for orange, and gradual effects that trigger once-a-turn could be a heavy theme. Some cards/effects that I could see moving to orange would be Paradox Haze, Disowned Ancestor, Instill Energy, and Puppeteer. I also see it having some synergy with artifacts, particularly with regards to the graveyard (scrapping and scrounging). Argivian Restoration, Treasure Hunter, and Kuldotha Forgemaster abilities could be orange as well. As the slow and steady color, defender synergy also makes sense. As scrappy, tough underdogs, orange mages probably also have at least some access to weenie creatures. Above all, it's the color of incremental advantage. Orange creatures tend to have higher toughness than power. Mix and match these abilities, and you have a full color. It's closer to white than any other, but it is definitely not white.
Orange creature types include things like insects, scorpions, elementals, birds, lizards, beasts, skeletons, humans, goblins, kobolds, hounds, cats, rats, and other survivors. Maybe elves could be there, since they traditionally live very long lives. Classes would largely be shamans, warriors, and scouts.
Here are some orange cards.
Bleakhaven Harrier 2O
Creature- Goblin Scout (U)
T: Tap target creature.
2O: Untap Bleakhaven Harrier.
2/2
Ruinseeker 1O
Creature- Human Artificer (C)
T, Sacrifice an artifact: Add one mana of any color.
"The ancients built many useless things, and I know just how to use them."
1/3
Infninite Patience 4O
Enchantment (R)
Whenever a source would deal damage to you, prevent all but 3 of that damage.
At the beginning of your upkeep, choose one-
-Each player sacrifices an enchantment or land.
-Draw 2 cards then discard 2 cards.
Obstinate Frillback 1O
Creature- Lizard (C)
Vigilance, trample
The kobolds eventually abandoned that particular hill.
2/2
Orange Shard 1
Artifact (C)
1,T: Add one mana of any color.
3O, T: Untap target permanent.
Kobold Rallymates 3O
Creature- Kobold Warrior (U)
Other Kobolds you control get +1/+0.
At the beginning of your upkeep, create a 0/1 orange Kobold creature token.
2/3
Ancient Timeteller O
Creature- Elf Shaman (C)
Sacrifice Ancient Timeteller: Target player takes an additional upkeep step during their next turn. (The additional upkeep follows the normal upkeep.)
"I have lived five human lifetimes, and remember all of it." - Sakui of the Dead Bird clan
1/1
Crossbow Tower 3O
Creature- Wall Archer (C)
Defender
1,T: Crossbow Tower deals 1 damage to target creature.
The goblins hate the kobolds, the kobolds hate the humans, the humans hate everybody, and they all love the towers.
3/3
Three-Legged Sphinx 3OO
Creature- Sphinx (U)
Flying
At the beginning of your upkeep, draw a card, then discard a card.
Half blind, mostly toothless, and missing a leg. Still even large predators leave her alone.
1/5
Low-power cube enthusiast!
My 1570 card cube (no longer updated)
My 415 Peasant+ Artifact and Enchantment Cube
Ever-Expanding "Just throw it in" cube.
Just using the stuff that you laid out, I'll make a couple little designs to test the waters.
P= Purple
Scuttling Quartzic 2P
Creature- Crystal Scout (C)
As long as Scuttling Quartzic is untapped, spells and abilities that target it cost an additional 3.
3/2
Quartzic Pother P
Creature- Crystal Rogue
When Quartzic Pother deals combat damage to a player, you may sacrifice it. If you do, that player discards a cards.
1/1
Foolish Cowardice P
Enchantment- Aura
Enchant Creature
Enchanted creature is a Coward in addition to other creature types.
Cowards can't attack.
(Colorshifted Guard Duty)
Purple does seem to work, and I think Cavern as the land lends something nice to it. It represents a human sort of dishonesty, but also has an instinctive feel. Mechanically, it is hard to bring this out of Dimir's wheelhouse. The logical abilities are protective keywords, evasion, card advantage, and hand disruption, all of which are decidedly Dimir. However, I could see things like Enchantment/ Aura synergy being present here (as a representation of mental tampering).
L = Yellow
Infinitude of Thought 2L
Enchantment- Aura (U)
Enchant Creature
Enchanted creature can't attack or block, and has "2L, T: Draw a card."
Austere Ascetic 4L
Creature- Human Shaman (R)
Hexproof, Indestructible, Vigilance
1/1
Horizon's Hold 1L
Sorcery
Search your library for a basic land card and put that card onto the battlefield tapped. Then shuffle your library.
(Colorshifted Rampant Growth)
This shares a lot of space with Beige. Because of the desert subtype, Desert doesn't work as this color's land. This is going to share some space with Abzan. Landfall makes sense here, as well as other land-based strategies. It isn't that hard to design for this color mechanically, but the flavor is often going to end up being dull.
O= Orange
Ruins of Old Baloura
Land- Ruins (R)
(T: Add O.)
Ruins of Old Baloura enters the battlefield tapped.
When a spell or ability controlled by an opponent destroys a creature you control, you may create a 1/1 orange Survivor creature token if you control no other creatures.
Kobold Crewmaster XO
Creature- Kobold Soldier (R)
When Kobold Crewmaster enters the battlefield, create X 0/1 orange Kobold creature tokens.
Other Kobold creatures get +1/+0.
1/1
Blast 1O
Instant
Destroy target artifact or enchantment.
(Colorshifted Disenchent/ Naturalize)
Ruins are a perfect land for this. This color feels very red/white. Besides being tough and doing red things, though, there's not that much to design for this color. Perhaps artifact synergy should be placed here.
E= Brown
Eaten By Ants 3E
Sorcery (U)
Destroy target creature. Each player creates 2 1/1 brown Insect creature tokens.
Hungering Deepkin 4E
Creature- Beast (C)
Bloodshed- When this creature kills another creature in combat, or deals combat damage to a player, put a +1/+1 counter on it.
4/5
Fall Below 1E
Instant
Target creature gets -3/-3 until end of turn.
(Colorshifted Last Gasp)
Yes, brown is very green. Mechanically, I think it will feel very green/black, and won't be that hard to design for. There are always baddies in the woods. Unlike green, this doesn't feel like the ramp color. Perhaps that's more yellow. This color will be creature focused, but looks like it could be a solid removal color.
K= Pink
Shared Prayers 3K
Instant (C)
Equality 1K (If you cast this card for its Equality cost, it affects each player instead of just you.)
You draw two cards.
Doddering Elf K
Creature- Elf
Remain (You may choose not to untap Doddering elf during your untap step).
2: Tap or untap Doddering Elf.
As long as Doddering elf is tapped, all creatures get +0/+1.
1/1
Soul Singer K
Creature- Human Cleric (C)
Whenever another creature enters the battlefield, you gain 1 life.
1/1
(Colorshifted Soul Warden)
This color feels shallow. It's too nice and happy all the time. Perhaps nationalism and blind loyalty should be added to its characteristics. Right now, there's not much to do with this outside of white, and group-hug abilities. It would make sense if this were also a color for aggressive zealots who will do anything good or bad for their beliefs. But again, all that kinda just seems like white. Perhaps if the color were mechanically tied to something major, it would help. For example, it would be interesting to make this a graveyard color. It may not seem obvious with pink, but it could also be the color of ancestors, heritage, and history. There isn't a clear graveyard color among these, so it's a logical fit. I could also see Silver, Yellow, Brown, and Beige working with the graveyard in various ways. I also think that "Village" would be a better land for this color than "City".
D= Gold
Ignoble Sellsword D
Creature- Human Mercenary Warrior (U)
First Strike
3: Put a price counter on Ignoble Sellwsord, and gain control of it. Any opponent may activate this ability if they pay an additional 1 for each price counter on Ignoble Sellsword.
3/2
Lothrid's Coffers 3
Artifact (U)
1D: Add 1 to your Wealth.
You may spend Wealth instead of D mana.
Ruthless Dracobaron 4DD
Creature- Dragon
Flying
Whenever you sacrifice a creature, target opponent sacrifices a creature.
4/4
(Colorshifted Ruthless Deathfang)
This color feels like one of the easiest to design for mechanically. You have shifting loyalties to work with, resource management (a decent color for ramp), aggro potential, and so on. There's a lot money can buy, and there are a lot of mechanical options here.
I= Beige
Distant Eye I
Creature- Eye (U)
Flying
1: Distant Eye gets +1/+0 until end of turn. You may look at target player's hand.
-3/1
Esoteric Puzzle 2
Artifact
T: Add P, O, L, E, K, D, I, N, V, or S.
III, T: Create a 5/1 beige Horror creature token. Exile it at the beginning of the next end step. (It doesn't have haste)
Observer of the Strange 1I
Creature- Human Wizard
When Observer of the Strange dies, draw a card.
1/1
(Colorshifted Oculus)
This treads the line between blue and eldrazi (colorless). It's not that hard to design for mechanically, as you can always throw your leftover designs to the weirdo.
N= Turquoise
Mad Sharkfolk 2N
Creature- Fish Shaman (U)
When Mad Sharkfolk Attacks, discard a card.
Bloodshed- When this creature kills another creature in combat, or deals combat damage to a player, draw 2 cards.
3/3
Inspired Frenzy N
Enchantment- Aura
Enchant Creature
Enchanted creature has haste, and attacks each turn if able.
When enchanted creature attacks, spells its controller controls cost 1 or N less to cast until end of turn.
Tempest of the Mind 1N
Sorcery
As an additional cost to cast this spell, discard two cards.
Draw three cards.
(Colorshifted Cathartic Reunion)
This falls right into the red/blue zone. Mechanically, it's not hard to design for, but it feels like anything I can come up with is either a red or blue ability.
V= Silver
Wry Arcanist 1V
Creature- Human Wizard (U)
Instant and sorcery cards you own are arcane.
8V: Return target instant or sorcery card from your graveyard to your hand.
1/2
Shrill Cantor V
Creature- Human Cleric (R)
Spells cost your opponents 1 more to cast during your turn.
Spells cost you 1 less to cast during your opponents' turns.
0/1
Questing Arcanist 2V
Creature — Human Wizard
When ~ enters the battlefield, you may search your library for an instant or sorcery card with converted mana cost 2 or less, reveal it, put it into your hand, then shuffle your library.
1/1
(Colorshifted Spellseeker)
Wizards and clerics. This feels like it will be easy to design for conceptually, but a little tougher mechanically. It is an interesting mix of Izzet and Orzhov. I find this color interesting.
S= Grey (instead of silver for some reason)
Weeping Mummer S
Creature- Elf Clown (C)
T, Exert Weeping Mummer: Lands and creatures enter the battlefield tapped this turn.
1/1
Mournfulness S
Instant (C)
Target creature doesn't untap during its controller's next untap step. Draw a card.
Muffle 1S
Instant
Counter target spell unless its controller pays 3.
(Colorshifted Mana Leak)
This one is tough. Who wants a whole color based on melancholy? Nevertheless, it lends plenty of design space, it's just not going to produce cards that are fun to play against. I instantly got the image of these weird, sad, black-and-white clown people, sort of like the opposite of the cult of Rakdos. There'll end up being plenty to work with here. The lands can't be tundras though. Tundra is a card.
Absolutely, my feeling is that THIS WORKS!! But, it only works as an alternate color pie. All of the concepts you've explored are placeable within the existing color pie. Obviously, Wizards is never ever ever going to do anything like this, but that shouldn't stop you. I think a set using these as the colors could be made, and could be really cool.
The main thing is that every player needs to have easy access to "add one mana of any color" effects. The inherent cost for adding multiple types of mana is less here, so I think you could and should have something like this at common:
Ruined Promenade
Land
Ruined Promenade enters the battlefield tapped.
T: Add O or L.
2,T: Add one mana of any color.
Low-power cube enthusiast!
My 1570 card cube (no longer updated)
My 415 Peasant+ Artifact and Enchantment Cube
Ever-Expanding "Just throw it in" cube.