How do I make a button text color change only while highlighted by mouseover?
 

There's an addon applying a SetHighlightTexture to buttons while the buttons are highlighted by mouseover, but that texture would look better if the button's text color also changed to black.

The button's default color is already being changed to white (255, 255, 255), but I want to write a code where the button's text color is changed to black while mouseovered.

How do I do this?

Edit: and how do I change the QuestMapFrame.DetailsFrame's text color?