Something's wrong with my MacBook...

I have no idea what happened but like a few days ago it just started to happen. Some parts of a window, which used to be gray, turns white. It's just some parts of an application window. It also happens on Facebook; when we have comments on stuff they usually have a small box with a different color under the thing we're commenting. But now it's just white so it blends in with the background. It also happens to other parts of Faceboook too. Some pics of whatever that is:

That's my Microsoft Word window toolbar. See the background of the part with "New" on it and the "Final Showing Markup" below it has different colors, but it used to be the same. It used to be the color of the bottom part, now it's just lighter for some reason...

 

Rows 1, 3, and 5 of my System Preferences window suddenly became white, even though it was greyish before.

And apparently this is happening to all Preferences windows of my applications:

[Adium, Firefox, Word]

Toolbox (or whatever that's called) nya Facebook biasanya beda warna skr jd putih nge blend sm page background nya...

I have no idea what happened, and I don't know how to fix this... Please help!!!!