I changed the background color that is visible when hovering code (to black). For example when you hover over a method, you see its signature in a box; I mean the background color of that box.
I want to rechange it but I don't find the property anywhere. Do you know which property it is?
(It should be a global property, because other boxes use the same background color, even the heap status box).
It might be too late. But I think you need to change this from your OS.
System->Preference->Appearance->Customise->Colors->Tooltips
solved my problem.
I am using Ubuntu 10.04.