Hi Mario, I'll include two different ways you could do this in Chimera 1.1700: ---------------- with menu ---------------- Actions... Atoms/Bonds... hide Actions... Ribbon... show Actions... Ribbon... edged Actions... Color... white Select... Structure... secondary structure... helix Actions... Color... red Select... Structure... secondary structure... sheet Actions... Color... cyan Select... Clear selection ---------------- with commands ---------------- ~display ribbon ribrepr edged ribcolor white ribcolor red :/isHelix ribcolor cyan :/isSheet ---------------- In both approaches, first the atoms are undisplayed, then the ribbon is turned on. The step setting the ribbon type to "edged" is optional; you could use whichever ribbon type you want. Then, I make everything white before making helices red and strands cyan. The reason I don't use the turn descriptor is that it only applies to explicit PDB TURN records, whereas in most cases, the PDB only contains HELIX and SHEET records. You could just put the commands in a plain text file, for example named "sscolor.com," and then use the command "source sscolor.com" to execute all the commands in the file. (The file must be in the working directory; otherwise you will have to include the whole path in the source command.) I hope this helps! Elaine =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Elaine C. Meng, Ph.D. Computer Graphics Lab and Babbitt Lab meng@cgl.ucsf.edu http://www.cgl.ucsf.edu/home/meng/index.html =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=