Theme colours - Text colour to not be defined by a background colour

The colour of the text in many areas is defined by the property “Shade1 background colour”. Background colours are typically the opposite contrast needed to a text colour.

Therefore it’s incredibly difficult to use the right colours.

Is there anyway to break these components out in your theme editor, or an ability to use a CSS editor?

Or ideally to have the “Header Text Colour” extend to all areas where the “Header Background Colour” is used?