Ability to create custom classes in overrides

[kaywyeex]

• This is not a v0.x issue.
• I have searched the issues of this repository and believe that this is not a duplicate.

Expected Behavior 🤔

Addition of an unknown class in overrides(or elsewhere), should make it possible to use to the given className matching prop on a component.

Current Behavior 😯

It currently throws a warning, saying that the class you're trying to override doesn't exist. Which makes sense!

Examples 🌈

Theme

    MuiTypography: {
      colorSuccess: {
        color: green[500]
      }
    }

Component

<Typography color="success" />

Context 🔦

I find myself wanting to use additional colors (eg. green for success) on components like Typography on occasion, and noticed it figures out the color by matching capitalized props against the classes.

This presented me with the idea of adding my own prop (colorSuccess), in the hopes that I would be able to use it globally, on a Mui imported component.

This however, doesn't seem possible today. Unless I've missed something?
I could see an argument against this, (transparency?), however in a large project with several people, this would be a pretty dope feature, since it prevents you from having to repeat class implementations (or create yet another file in /components/).

Thanks in advance!

[eps1lon]

This is technically possible currently: https://codesandbox.io/s/zyjwxqj04. However it relies on implementation details.

We're working on a better color prop API (see #13875) that should cover this use case. For more advanced overrides I would recommend using your own wrapper component. We can't cover every single use case via props only.

[oliviertassinari]

Could it be a duplicate of #13875?

The success, danger, warning and info are values I think that we should support by default.

[kaywyeex]

@eps1lon
Agreed, however it logs a warning in the console, which is why I figured one should probably shy away from doing so. 🤔

@oliviertassinari
I agree with the default values you mentioned, given those are the ones we usually find using the most. Would probably also be less painful to implement than custom colors.(?) 💯

[roflc0pter]

Is this in progress? Otherwise I would like to contribute.

[oliviertassinari]

I'm closing for #13875. We have solved most of the infrastructure issues. Now, it's about making sure it works end-to-end with each use cases