WIN2K - Terminal-Server. Colors problem

hi,

my application has a color-design which use 3 special
colors, that looks very bad on a client of a terminal
server.
if i set the background of the desktop of a certain client
to one of the 3 special colors, that one looks ok. i tried
to add this special colors to the custom-pallete in the
display settings-appereance. and also defined the special
colors in in the registry: HKEY_CURRENT_USER\Control
Panel\Custom Colors

any more ideas?
thanks,
edo.