Hi Don, You could pull the RGB colors out of your ColorControl or ColorAlphaControl, pass them through the fromReference() method of an HSVCoordinateSystem (transforms RGB to HSV), decrease the saturation of each color, then pass them back through the toReference() method of the HSVCoordinateSystem and put the resulting RGB values back into your Color*Control. You can run 'java HSVDisplay' in the visad/examples directory to get a feel for HSV color coordinates. You'll have to experiment to determine whether decreasing saturation gives the desired result, or one of the methods that Curtis suggested. Good luck, Bill On Wed, 25 Jan 2006, Don Murray wrote: > We have various displays where we map data to RGB or RGBA. > One of the users asked if we could tone down the saturation > of a particular background topography image so that data > overlain on top stands out more. > > Not knowing anything about color, I tried adding in a > ConstantMap of .5 to Saturation, but that had no effect. > > I though of using transparency, but that is going to be > order dependent so isn't really a solution. > > For a given color pallete, what's the best way to "mute" > or "tone down" the colors?