Kolourpaint already provides the ability to Save, Save as, Open and reload custom colors files. However, those features are only based on colors configuration files that you must save somewhere.

Could you add the possibility to save colors files in kolourpaint configuration, providing another section similar to KDE colors? That would skip remembering where the colors saved file is located and also provide a better colors selection method on a new "custom kolourpaint colors" menu selector (rather to find out again where the colors saved file is located). 

That is, to store colors configuration files "inside kolourpaint" in addition to files.