Material Editor > Maps rollout > Click a Map button. > Material/Map Browser > RGB Tint
RGB Tint adjusts the value of the three color channels in an image. Three color swatches represent these channels. Changing a color swatch adjusts the value of its associated color channel.
The channels are named Red, Green, and Blue for their default colors, but you can assign them any color. You are not limited to variations of red, green, and blue.
To tint a map:
In the RGB Tint Parameters rollout, click the Map button marked None.
Click the R, G, or B color swatch.
The Color Selector is displayed.
The red, green, or blue value of each pixel in the underlying map changes accordingly.

R/G/B—The red, green, and blue color swatches display the Color Selector to adjust the value of the specific channel.
Map—Displays the Material/Map Browser to select the map to be tinted.