Hi Elaine, I am looking into using CHIMERA to create a diagram. Each residue will be coloured according to an assigned value; say if the value is high, the residue will assume a bright red colour; if the value is low, the residue will be coloured light yellow; residue with a medium value will appear somewhat orange. So my question will be: is there a way to specify the colour of a residue by its RGB value? And how does the command look like (as I will be scripting to do it in large scale)? Thanks! =] Cheers, Sumitro Institute for Infocomm Research disclaimer: "This email is confidential and may be privileged. If you are not the intended recipient, please delete it and notify us immediately. Please do not copy or use it for any purpose, or disclose its contents to any other person. Thank you."