I added two white images to two buttons in a tableView ，but when I simulated my code， one of the image turned in grey :( And sometimes it appeared just right.
I do not have 10 reputation now，so I'can add an image here，sorry！:(
I have referenced two image with the same name, where one of them is gray and the other is white.
The most stupid thing was that I ignored the warning:
***Multiple build commands for output file /Developer/B/Be/build/Release-iphonesimulator/BB.app/no.pn***g