graphic problems

Hallo,
Is there anyone you is an expert in old sparc hardware ?
I have a problem with my "new" ( sparc 20 ,2xCPU,250MB) sparc.
For me it is not possible to enhanc the colors of my graphic adaptor.(STP3010PGA TURBOXGX SUN)
Is there a chance to adjust more then 256 colors ?

Please help my !

From Usenet:
(http://groups.google.com/groups?selm=36E55185.F0A9C47%40brockport.edu&output=gplain\)

"The turboGX is another version of the venerable CG6, which is an 8-bit accelerated framebuffer capable of 1152x900 maximum resolution. You're
limited to 256 colors irregardless, and a maximum resolution of 1152x900. There are no configuration files; resolution can be turned down in the PROM (at the ok prompt)."