Background

[pitbull51067]

Description

When turned to dark mode, the background color behind the puzzle wouldn't change. It appeared to be hardcoded so I made the necessary fixes to make it flexible so it can change depending on if it dark mode or not.

Closes #467

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [x] Enhancement (improvement to an already existing feature)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

I opened every puzzle file on LEGUP and changed the preferences to dark mode/light mode and the background changed accordingly every time

Checklist:

• [x] I have performed a self-review of my code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation (if applicable)
• [x] My changes generate no new warnings
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[jadeandtea]

Looks like the tests are failing. Can you take a look at them?

[jadeandtea]

Merging this into a branch so that others can work on the fillapix tests.