Autohilite Color -- How to Set?

[Brahmanathaswami]

What determines the color that appears when "autohilite" is set to true 
for a button? And how can we change it?

Sometimes, on mousedown, I'm getting a dark blue with black type. I 
would like to be able to set that color but I'm not seeing any dark blue 
in the color properties for the button(s). It seems to be some kind of 
"reverse out" algorithm?


BR