Starting at PyMOL 1.4, single color for the background is no longer the only choice. By using 3 PyMOL commands, the gradient background color can be easily shown. The only thing users have to know is that command “ray” doesn’t support this gradient color yet. So if you type “ray” in the pymol terminal , the gradient color will show off.
Here is what I did (use PyMOL 1.4) at get the following picture:
set bg_rgb_top, [0,255,0]
set bg_rgb_bottom, [0,255,255]
set bg_gradient, on