Comment # 3 on bug 941868 from 1st last

It does *not* work for me with openSUSE 13.1, Thunderbird 38.3.0, and Lightning
4.0.3.1

I click
Edit->Preferences->Calendar->Categories
Then I highlight any category, then I click the button
'Edit...'
This opens a window with title 'Edit Category' and a  'Color' button.
I click this button.
This opens a window with title 'Choose a color'.
In the latter window *no* element be modified and *no* button does anything.
In turn none of the category colors can be changed.

I would hope that a fix will not boil down to the suggestion to upgrade to
openSUSE 13.2