24bit support on dec3000 ?

[Aleksandrs Livshics <aleks.l%mpe.lv@localhost>]

I am using NetBSD on an old Dec3000/700 and I have 
recently got a 8 and 24 bit graph. device pmagb-j. It is supported
and console is OK. When I start X, I get crazy colors (it does not happen
with 8bit only device pmagb ). Is there anything that can be done to fix 
the problem or NetBSD's X for alpha does not support the device ?  
Can it run at least in 8bit mode properly? Can the mode 8/24 be chosen
in any way?
Can't find the answer in the documentation.
Alex