change color

hello

I want to color the particles by region.But I found that only the combination of 255 and 0 can change color,such as (255, 0, 255)(0, 255, 255)(0,0,0).If I use other combination ,the color will be white.Is it because yade only shows a few colors?

I would appreciate if you can help me

James

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for b in O.bodies:
         if isinstance(b.shape,Sphere):
   if b.state.pos[2]>0 and b.state.pos[2]<cut*0.25:
    if b.state.pos[1]>0 and b.state.pos[1]<((ylength)*0.25):
     b.shape.color=(108, 51, 101)
    elif b.state.pos[1]>((ylength)*0.25) and b.state.pos[1]<((ylength)*0.5):
     b.shape.color=(72, 72, 147)