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.

 
 
OneTwo

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.

Even if your eyes happen to be good enough to spot the difference, it's still not a very obvious difference.