Specify an explicit text colour on some components that change the background colour

Specify an explicit text colour on some components that change the background colour

These components separate themselves from the default colouring of the content
area by specifying a dedicated – typically light grey – background colour.

However they leave text colour unspecified and as a result if the skin should be
white on black instead of black on white this results in these components becoming
white on white or white on light grey and becoming unreadable.

Fix this by explicitly specifying a text colour to use where the background colour is set.

Bug: T66732
Change-Id: I12584de40a18929b610d46dceaea73f06fdc6541