I am talking about this background color underneath droparea variable, see screenshot:
My color scheme would be perfect if I get just that resolved.
The Category you are looking for is Mark Occurrences, but it is language specific so you won't find it under All Languages. You will see it when you change the Language to Java for instance. Then you have to change the Background field on the right hand side.
来源：https://stackoverflow.com/questions/9709787/how-to-change-the-highlight-variable-color-in-netbeans-ide