I presume you mean that ACR ( not PS, as you said) is displaying the image incorrectly, right?
If so, probably the single most common problem is that you accidentally set the default raw rendering preset in ACR to something fairly extreme. The solution is reset the ACR default to the factory default.
To see if this is the problem, click on the last yellow menu item shown in the attached screen shot (from CS6).
If this doesn't work, or the problem isn't in ACR, please give us a LOT more details starting with which version of PS you are running. Also post a copy of a raw file that is giving you problems so that we can open it on our own machines. Finally, give us the history of the file you just sent. For example, if it's a Nikon raw file, might you have first processed it in Nikon's Capture NX2, and then are re-opening it ACR?
Cheers,
Tom M