fix: fix some invalid color-styles

[Mat2095]

They were using rgba() in an incorrect way or used undefined variables.
Closes #636
Also fixes wrong import-path in _datepicker.scss

Proposed changes

Screenshots (if appropriate) or codepen:

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to change).

Checklist:

• I have read the CONTRIBUTING document.
• My commit messages follows the conventional commit format
• My change requires a change to the documentation, and updated it accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[gselderslaghs]

Looks good, thanks for your first contribution

@wuda-io can you take a look as wel? Not sure why the sass linter did not notice the incorrect import-path in pr #608

[Mat2095]

I'm not sure, but I noticed when I change the path to something like ../foo/mixins.module.scss, it does fail to build with npm run build. So I think sass actually does find the file with ./mixins.module.scss.
But when running pnpm dev in materialize-docs, it fails to build:

[plugin:vite:css] [sass] Can't find stylesheet to import.
  ╷
1 │ @use './mixins.module.scss' as *;

  │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  ╵
  packages\materialize\components\datepicker\_datepicker.scss 1:1  @forward
  packages\materialize\sass\materialize.scss 38:1                  @import
  src\style.scss 2:9                                               root stylesheet

So my guess is that rollup configures sass to look in additional locations to find imports compared to vite. Or it might be because the project-root is different in the two cases.

[wuda-io]

LGTM

[gselderslaghs]

Approved, works as expected 🚀

[wuda-io]

Good work, thanks for your contribution @Mat2095. I will invite you to join the Team.

[Mat2095]

Thanks, I can accept, but I don't think I'll be able to contribute, since I'm not actually using materialize 2. The project I'm working on is still using materialize 1 with no plan of migrating in sight. I think I was looking at materialize 2's output CSS for a comparison when I noticed those invalid CSS rules.