Remove Color Casts?

There are a bunch of ways to do this, like by using either Curves or Levels (the way we’re doing it here, it works the same way with either). So, press Command-M (PC: Ctrl-M) to bring up the Curves dialog, then click on the middle eyedropper (the one half-filled with light gray) beneath the histogram. Now, click on something in your image that’s supposed to be a light gray, and that will take care of the color cast. If you click it and it doesn’t look right, try clicking it somewhere else. My preferred method, though, would be to open Camera Raw and use the White Balance tool: Go under the Filter menu and choose Camera Raw Filter. When the Camera Raw window appears, get the White Balance tool (I) from the toolbar up top and click on something in the image that’s supposed to be light gray. Again, if you click it and it doesn’t look right, try clicking it somewhere else until it looks right to you.