Change floating label placeholder's color

[TommasoAllegretti]

Description

Changed the floating labels placeholder's text color from black to light gray (opacity: 0.65). I removed the styling from the other label tags under .form-select and .form-control:-webkit-autofill parents as every label should now have the same behavior.

Motivation & Context

As requested in issue #39420

Type of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Refactoring (non-breaking change)
• [ ] Breaking change (fix or feature that would change existing functionality)

Checklist

• [x] I have read the contributing guidelines
• [x] My code follows the code style of the project (using npm run lint)
• [ ] My change introduces changes to the documentation
• [ ] I have updated the documentation accordingly
• [ ] I have added tests to cover my changes
• [ ] All new and existing tests passed

Live previews

https://deploy-preview-39494--twbs-bootstrap.netlify.app/docs/5.3/forms/floating-labels/#example/

Related issues

#39420

[theodorejb]

👍 Yes! I've often been confused by the current text color since it looks like a value rather than a placeholder.

[louismaximepiton]

I think it's fine as-is.

[theodorejb]

Is there anything preventing this from being merged?

[julien-deramond]

Is there anything preventing this from being merged?

For the moment, the target of this one is v5.4.0. The next version will probably be a v5.3.x. We'll evaluate when to merge it at the appropriate time.