New LuxFooter component Light Theme needs different colors

[sdellis]

Current display

The current <lux-footer theme='light' /> variation has a white background. This looks strange on pages that already have a white background because it doesn't differentiate the footer from the rest of the page. There is also text that is invisible to the eye because it's white-on-white.

Desired display

The light theme should have an off-white background var(--color-grayscale-warm-lighter) and the text should be var(--color-rich-black). This is a screen shot of the old color scheme for reference.

Acceptance criteria

• I can successfully use this feature with Voice Over in Safari.
• I have checked this feature using one of the following browser extensions and confirmed that it does not add any level A or level AA issues:
  • axe dev tools
  • Lighthouse
  • Wave
• ...

Notes

This is currently an Accessibility issue as well since there is no contrast between the background and some text.