Basically, I feel as though a good way to fix the color fixing problem in MTG is to create more Basic lands so that people don't need to spend hundreds of dollars
The first of these is my dual concept
"Basic WU
Basic Land
This card enters the battlefield tapped.
When Basic WU enters the battlefield, sacrifice unless you pay {1}.
{t}: Add {w} or {u}"
So with this you see that I want the cost of making a card have no deck limit high
Now the Trip version
"Basic WUB
Basic Land
This card enters the battlefield tapped.
When Basic WUB enters the battlefield, sacrifice unless you pay {2} and return a land you control to its owner’s hand.
{t}: Add {w}, {u}, or {b}"
The duel looks good, but the trip is an unplayable hot steaming pile.
The trip in this time could just be enters tapped and bounces a land. Kinda like the Rav bounce lands except you don't actually lose ground by playing them. This one you do lose ground but at the same time color fix very well. It's such a liability you could probably give them the land types. Just look at the trioams. They are better but have the 4 of rule in effect.
Tri land that doesn't enter tapped.
Basic
When ~ enters the battlefield each opponent may scry 2.
Tap: add w,u,or g.
Realistically, the vanillia comes into play tapped duals (Cinder Barrens) could probably be Basic. The tempo delay of coming into play tapped is a not insignificant cost, which is why Shock lands and the like are so valuable, because you can avoid that cost. If you played a deck of nothing but those duals, you'd constantly be a turn behind for the whole game.
Tri lands are trickier, but something akin to Gateway Plaza would likely be balanced as basic if limited to three colors at a time and a deck of all these lands would be two turns behind the whole game (except that that they literally cannot be played as the only lands in the deck, because you'd never be able to play one).
Land like this, though, would make cards that search for basic lands far more powerful. Land search was very strong in Tarkir-BFZ Standard and everything devolved into 4-5 color good stuff decks, and Basics that can make multiple colors make those kinds of decks that much easier.
The first of these is my dual concept
"Basic WU
Basic Land
This card enters the battlefield tapped.
When Basic WU enters the battlefield, sacrifice unless you pay {1}.
{t}: Add {w} or {u}"
So with this you see that I want the cost of making a card have no deck limit high
Now the Trip version
"Basic WUB
Basic Land
This card enters the battlefield tapped.
When Basic WUB enters the battlefield, sacrifice unless you pay {2} and return a land you control to its owner’s hand.
{t}: Add {w}, {u}, or {b}"
The trip in this time could just be enters tapped and bounces a land. Kinda like the Rav bounce lands except you don't actually lose ground by playing them. This one you do lose ground but at the same time color fix very well. It's such a liability you could probably give them the land types. Just look at the trioams. They are better but have the 4 of rule in effect.
Tri land that doesn't enter tapped.
Basic
When ~ enters the battlefield each opponent may scry 2.
Tap: add w,u,or g.
Tri lands are trickier, but something akin to Gateway Plaza would likely be balanced as basic if limited to three colors at a time and a deck of all these lands would be two turns behind the whole game (except that that they literally cannot be played as the only lands in the deck, because you'd never be able to play one).
Land like this, though, would make cards that search for basic lands far more powerful. Land search was very strong in Tarkir-BFZ Standard and everything devolved into 4-5 color good stuff decks, and Basics that can make multiple colors make those kinds of decks that much easier.