Ah. Never heard of Kolourpaint. I only use GIMP for animation. For actual image manipulation and drawing I use Photoshop Elements. I also use Paint.NET occasionally for quick, tablet-less manipulation because it loads faster, and is also what I used before I got my tablet and PSE. I'd recommend Paint.NET. It has the simplicity of mspaint - which from GIS, Kolourpaint seems similar to - and some of the higher functionality of the better image manipulators like GIMP and Photoshop, like layers and transparency. It is also free.