Steps to create a Color Mask and set multiple colors in a raster image transparent in Raster Manager
A Color Mask can be used when working with Color and Grayscale raster images when using tools in Descartes like the Vectorization tool, which is used to convert raster data to vector data.
The area that matches that color will then be transparent. If a color is not transparent then it may be that the area that you want to be transparent is made up of different colors that are close, but not the same color. In this case they colors will have to be added to the color mask.
Frank McAllister