I think it would be a bit more user friendly if a new category will be added/name of category will be changed when the user click on the “Add” button at the bottom of the Category List Windows. E.g. by entering a color code in that box would be nice.
I have tested it, i do not think it can save the custom colour on the custom colour option.
Another feature that would be good is to allow user to click on the Color column to edit/change the colour that the user prefer in the Category List windows would be good. At the moment the user can only change the colour of the category in the “Category Properties Windows”
And also If the user is allowed to add a new or remove the existing category in the “Category Properties Windows” by clicking on a Add/Remove button would make it more convenient as well.
Please let me know if you want me to explain more.