In Themes, why does 'Reset to Default Value' result in black? If you change a color in User Preferences > Themes, and then try to change it back to it's default by Right click > Reset to Default Value: 



It just makes R=0, G=0 and B=0, (Black)! Why?



I know there is a 'Reset to Default Theme' button at the bottom of the Preferences window, but that resets the whole Theme.
As it says in this bug report,  there are some default values which are hardcoded into blender, and not read from the startup .blend  (which is what the Reset To Default Value operator does)

This is a known bug on the blender wiki todo list.