To everyone suffering from the error message "grass cannot create
read/write color cells" I had success with a simple fix. In starting an
xwindows session in RH6.0 with the startx command the session would
automatically default to 256 colors...not enough, especially when you
have things like backgrounds eating up color. My graphics card supports
16 bit color so to utilize this color depth I use:
startx -- -bpp 16
This eliminated the error message when displaying raster maps.
Hope this helps,
Mike Crimmins