UIU-3013 - Refactor feefines css away from color() function

[JohnC-80]

https://issues.folio.org/browse/UIU-3013

Minor CSS refactor as we strive to eliminate a non-spec postcss- dependency. This doesn't change appearance, just implementation. The spec for color() has changed - and native color() does not function in the same way that we use it in a number of places - in this case, to obtain a contrasted version and then blend it with the original...

oklch colorspace is a new color space that assures better, more accessible outcomes to color adjustment.
CSS color-adjustment syntax (from ...) is a new feature that allows for adjustment of pre-existing colors.
color-mix() is a native function that can be used to blend colors.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
No Duplication information