g.region raster=elevation -p r.rgb input=elevation red=elevation.r green=elevation.g blue=elevation.b
In this case r.rgb produces in the current mapset three new raster maps - 'elevation.r', 'elevation.g', 'elevation.b'.
Last changed: $Date: 2016-03-18 15:09:00 +0100 (Fri, 18 Mar 2016) $