Mattes button doesn't work

Hi there. I’ve been using Mocha for about two hours now and I’ve got a small problem.

The Mattes button does not appear to work as the manual says it should. If I click on it with “colorize” activated, it just turns the whole image a solid color. If I deactivate “colorize”, the Mattes button does nothing. It does not appear to matter how many splines I have, or whether a spline is selected or not. Am I missing something?

Thanks for any help!

To close this thread out, I believe the display preferences in Windows was set to 16 and not 32.