[Chimera-users] CHIMERA help - coloring density maps

Hi, I have just started using CHIMERA to look at volume files in the CCP4 format for virus particles. I would like to color the density as a color ramp continuously changing between ANY two specified colors depending on the radial distance from the center of the virus particle (as shown in the attached figure). How do I achieve this with CHIMERA? thank you very much for your help in advance. -Padma