yeah, that's what i was doing

i'm not sure how to mix colours and have bits where it's distinctly blue and distinctly brown and other parts where it's harder to tell

originally i took the two layers and erased bits out from the brown layer, but then the transition between blue and brown was way too hard, even if the eraser had a soft edge. i thought maybe i could change the softness of the edge like you can control the drop off on the zbrush brushes, but didn't see where you could do it in cs3

in the end i just erased bits out at different opacities

didn't use the layer blending modes because i didn't see a mode that suited