Hi Sebastian, Short answer is no, custom coloring (such as Coulombic) is either all or none for a given surface. However, one possible workaround is to open two copies of the structure, surface both copies, show Coulombic coloring on one surface and green (or whatever non-Coulombic coloring you want, possibly multiple colors) on the other. Then unsurf (~surf) the set of atoms you *don't* want to show Coulombic coloring for in the Coulombic copy and the other colors should show through. This presumes the Coulombic-colored surface "wins" display when two surfaces are shown in exactly the same place. It worked in my test, but it is possible you might have to try Coulombic-coloring the second copy instead of the first copy. I tried this and it looked reasonable. It might not look that good depending on the specific geometry of the surface. I also tried unsurfacing the complementary set of atoms in the other copy, but that looked terrible because there were gaps. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Nov 20, 2012, at 7:19 AM, Mock, Sebastian wrote:

Hi Chimera Team, is it possible to color the active site of an enzyme let’s say green after the coulombic coloring, without losing the last-mentioned? The coulombic coloring disappears when I try to color specific positions in the structure to green. Thanks in advance Sebastian