Minor color contrast fix

[richtabor]

Description

Closes #687 by switching the pattern to use an accent color as a background (which falls back to no color when no exact color slug is matched in a variation.

Screenshots

Testing Instructions

1. Open the site editor.
2. Switch to the "Maelstrom" style (it's blue).
3. Add a new page.
4. Open the inserter.
5. Search for cta-services-image-left within the pattern inserter.
6. See change.

Contributors

[MaggieCabrera]

This is not the only pattern that has contrast issues. The details block in the FAQ pattern looks even worse, and I haven´t checked all of the rest to see if there are other concerns. I will try to have a look today and see what I encounter

[richtabor]

I fixed the FAQ pattern. The rest look good.

[richtabor]

This highlights the need for WordPress/gutenberg#48581 and WordPress/gutenberg#53996 both.

Essentially we're limited on using alternate colors throughout variations, as we can't ensure there is appropriate contrast between every variations colors—other than base and contrast. With support for both of those issues, we can have much more color variation/adaptability between variations, allowing for more creativity/variance.

[MaggieCabrera]

I looked at all the patterns and they looked ok with this change and I don´t see the contrast issue in any of the rest. If we are ok with the background change in the context of the full page templates like the about one, I´m fine to get this in for RC2:

[MaggieCabrera]

This highlights the need for WordPress/gutenberg#48581 and WordPress/gutenberg#53996 both.

Essentially we're limited on using alternate colors throughout variations, as we can't ensure there is appropriate contrast between every variations colors—other than base and contrast. With support for both of those issues, we can have much more color variation/adaptability between variations, allowing for more creativity/variance.

Absolutely, +100000000