If I set new colours for Categories, the changes are applied instantly. But if I open the colour settings again, it is back to the default green. But the view still shows the colours chosen before.
After restarting korganizer all the category colours are back to default green.
Changing the colour data in korganizer.rc does not help because some changes are reverted by korganizer after restarting some are still set in the file but not used in korganizer.

Reproducible: Always

Steps to Reproduce:
1. Open configure KOrganizer
2. Open Colors and Fonts
3. Change category color of non-standard category
4. Apply changes
5. See that colors in week view have changed as desired
6. Open colour settings again
7. See that colors are back to default green.
8. Go back to week view -> see that applied changes still are in effect
9. Restart KOrganizer
10. See that none of the changes is still in effect and all the work was for nothing

Actual Results:  
Change of the category colors are back to default

Expected Results:  
Change of category colors should be as changed before

I use Linux Mint 17 XFCE and KOrganizer version 4.13.3