Color refinement for light and dark modes

[andrewtavis]

This issue is to refine colors in both light and dark mode implementations. ColorVariables.swift has all the coloration variables for Scribe keyboards, with these values being selected to work for an MVP release. There are surely better versions of many of these colors. The key and background colors could look more like the system keyboards, and annotation colors could look more consistent and show up better.

Adding further colors would be an extra step in this issue, as there is a likelihood that users will eventually be able to select which colors they want to use for annotations. In that case it would be best to have pre-set values for generic colors that they can choose from that will show up well on the backgrounds.

• Ideas on Scribe brand colors would also be appreciated if contributors are interested, which would be linked to Scribe key design  #24

[andrewtavis]

The pronouns and verb forms shown during Conjugate in dark mode are currently a bit hard to see. The ratio between the key color and these annotations, the same color as the command bar, specifically needs work.

[andrewtavis]

Closed via 6449021 for the design sprint in #112. Color palettes have now been updated, with readability now being dramatically better.