Ribcolor is equivalent to color with the ,r specifier.
Ribcolor assigns ribbon colors at the residue level. Even if only particular atoms are specified, the ribbon segment(s) corresponding to the entire residue(s) containing the atoms will be affected. The command ~ribcolor sets the ribbon colors to none (no color assigned), revealing the model-level color (see coloring hierarchy).
Color_name can be none or any color name that specifies a single color.
See also: ribbon, color, ribinsidecolor, modelcolor, rainbow, rangecolor, the Actions menu