09-26-2019, 07:49 AM
Makes me wonder what sort of message? 
Things to try out.
1. Posterize Colors -> Posterize You get more colours than the setting but it will reduce colours from 21000 (your clip) to 22 screenshot https://i.imgur.com/VC08d7Y.jpg
2. Convert to an indexed image Image -> Mode -> Indexed with a small number of colours (16 shown) . Edit the resulting colormap. https://i.imgur.com/B4w1ZnE.jpg
3. Tools -> GEGL Operation -> Color Warp Not a filter I know too much about apart from it is there. You can color pick or set both from and to colours. https://i.imgur.com/xDtoYpa.jpg
Things to try out.
1. Posterize Colors -> Posterize You get more colours than the setting but it will reduce colours from 21000 (your clip) to 22 screenshot https://i.imgur.com/VC08d7Y.jpg
2. Convert to an indexed image Image -> Mode -> Indexed with a small number of colours (16 shown) . Edit the resulting colormap. https://i.imgur.com/B4w1ZnE.jpg
3. Tools -> GEGL Operation -> Color Warp Not a filter I know too much about apart from it is there. You can color pick or set both from and to colours. https://i.imgur.com/xDtoYpa.jpg