Button colours do not match required Color Contrast

[philipbrembeck]

As the MWUI should also be accessible (e.g. to colour-blinds), it should match the required color contrast.
In the case of the Buttons, it does not.

[Fuasmattn]

This is a known issue and out of our hands. It's one of the brand colors and was chosen despite the fact of bad contrast unfortunately by the company