Is it just one skin?
If exclusive, try changing the explorer background through sks?
If tried already. try using a Windows skin, but make sure you open the task manager and stop wb services. Then make sure also you have no saved themes through Windows, then apply a Windows skin, then restart WB.
If all your skins are doing it, I would reinstall WB.
Unless you altered the code editor and this would only affect one skin!
Just by some weird circumstance, I notice the left side of the second image is also yellowish, that area is the folders bar area, check that image for corruption, and, in folders bar area of wb, check under extra settings and switch the color to see if it makes a difference. If not, I would suggest something may be wrong with your pc, some setting or driver, or registry error, not sure. Good luck!