03-16-2017, 08:52 PM
(03-16-2017, 08:24 PM)integrator Wrote: For some reason, it doesn't allow me to select anything. This was a autocad drawing which we exported as a .png and then open in Gimp.
Using color exchange you do not select anything. Click on the 'from' color and change that to red in the select dialog or use the sliders to adjust. The 'to' color should already be the default black. Then Ok that. All red in the image is changed to black - that is what you wanted isn't it?
Gimp docs (a bit dated) https://docs.gimp.org/en/plug-in-exchange.html