In Digikam 2.1.1 with the 'Default' theme on Ubuntu 11.10 the Tooltip title bar is white, with black text. The Tooltip menu (context-sensitive mouseover pop-up menu, e.g. Properties for images) is grey text on a black background - although I had to look really hard to see any text at all. It's unreadable. 

I tried to change it: Settings - Themes - Configuration - 'Colours' tab; select 'Tooltip Background' and change the sample colour from black to white then change 'Tooltip Text' from off-white to dark grey. It looks like it was meant to be white text on a black background, but that's not what shows up.

After I changed it, the tooltip still displays black text on a black background. This looks like bug 281108, which was fixed.

Secondly, the Tooltips often 'stick' on the screen if for example you bring up a menu, Digikam may leave the tooltip menu up. This isn't completely consistent. 

Reproducible: Always

Steps to Reproduce:
1. Mouseover anything with a tooltip, eg folder name, or image, and pause
2.
3.
Actual Results:  
Black Tooltip menu with white menu bar and black title comes up

Expected Results:  
Black menu text on white background