Default Palette differences Win98 vs WinNT vs Win2000


I have created a  pf8bit bitmap that looks great on my development
machine (Win2000). However, when I run my app on Win98 or WinNT 4, my
bitmap is (mostly) just black. It seems that the palette is quite
different by default. How do I go about defining a "universal" palette
for my bitmap so the appearence will be more consistent across
platforms (or at least visible!)

Thank you,