riva_wclut
riva_wclut(chip, regno, red >> 8, green >> 8, blue >> 8);
riva_wclut(chip, regno*8+i, red >> 8,
riva_wclut(chip, regno*8+i,
riva_wclut(chip, regno*4+i, r,
riva_wclut(chip, regno, red >> 8, green >> 8, blue >> 8);