Holy cow, I wrote a book!
Often people will say, "Oh, we can highlight by inverting the color."
This may have worked great on two-color black-and-white displays, but in the world
of 32-bit color this no longer is effective.
Consider the following picture. See if you can guess which one is inverted.
Answer: The one on the right is inverted.
The background color is gray, #808080. The box labelled "two" is highlighted by inversion.
The inverse of #808080 is #7F7F7F, which is practically the same color.