Reconsider some admin scheme colors.

[youknowriad]

In #50537 we explicitly excluded the ocean and coffee admin schemes from the colored buttons because the default button color there don't meet the contrast guidelines.

Also, the buttons in the midnight admin scheme are red and too close to buttons meaning "danger" or "error".

Instead of trying to fix this by tweaking the styles specifically for these admin schemes, I think we should address the root issue and potentially alter the highlight color for these admin scheme colors issue.

Alternatively, we consider consider retiring some of these admin scheme colors.

[afercia]

Related: #49999.