Thanks for your help, Al. You put me on the right track.

The problem turns out to be a stupid #$$ "feature" of the ancient, convoluted and almost undocumented framework I've been using since VFP6. (With several painfully difficult upgrades over the years!) It turns out that deep down at the lowest level of the framework it changes all controls' DisabledBackColors to the same as the DisabledBackColor of the parent container. AAARGH! I'm glad I didn't install that last update before the creators abandoned the project several years ago.

Anyway, since I have only two projects left in VFP, I think I'll save myself some grief and use my workaround. Both of the projects are large. I'll be rewriting one of them next year in .NET. The other one hasn't changed in several years except for minor tweaks and will probably die when the business owners retire in a few years.

I'll update my original post to indicate the error of my ways.

Thanks again,
...Jim