Contrast of unusable buttons is difficult to determine

[MichaelPetitclerc]

Feature Request

Problem
The contrast on some of the MatterControl preset background colors are difficult to see if an option is usable or not.

Solution
Adjust the contrast of the unusable button or add an offsetting color to show that an option is not usable. This could be added as an overlay option in settings under Accessibility or something similar.