We started out making games with Director 4 back when Windows only supported 8 bit palettes and monitors were 640×480. We chose a background color from the Mac Palette that is hex #0066FF. About 5 years ago we updated our movies so that they would fill the whole screen on larger monitors. Most of the backgrounds and menus Flash .swf files. They scale nicely at all resolutions. We had a bunch of backgrounds masks that are solid colors so we just transformed them to 16 bit bitmaps.
We’re updating a bunch of Director movies to D11.5 so that they will run on OSX Lion and our graphic designer noticed that the backgrounds weren’t exactly the right color. It turns out that Director, for its usual inscrutable reasons, didn’t map the Mac Palette color to #0066FF and they ended up being #0063FF instead. Transforming them back to 8 bit and then to 32 bit fixed the problem.