Refactor base colors to configurables directory. Allow customizing primary color for light and dark mode

[ddelnano]

Summary: Refactor base colors to configurables directory. Allow customizing primary color for light and dark mode

This change makes it possible to have different main colors for light and dark mode. The contrast difference between the light mode background and the text color scores poorly with the contrast checker.

Relevant Issues: N/A

Type of change: /kind cleanup

Test Plan: Tested UI to verify that it looks the same in light and dark mode

• [x] Verified all references to COLORS.PRIMARY[500] have been updated with new structure