Most advanced users skip the Auto command. And I admit, in the past, Auto wasn’t nearly as useful. But hidden within Auto are multiple methods for automatically analyzing and solving problems. One of those problems is color cast. And an adjustment layer with Auto curves has the ability to fix all sorts of color cast issues automatically for you instantly and accurately. Now, this image is a little bit of a color cast. It’s not bad, but it’s a tad green and it just doesn’t have the richness that I’d like.
Now, you could, of course, go after this manually, adding a Curves adjustment, and then switching to each channel. For example, if I pull the red up or down, you see how I can start to balance that image out. But it does get a little bit tricky. One of the things I like to suggest is to hold down the Option key or Alt key here and click on the word Auto. This is going to bring up a new dialog and what I want you to look at is this option called Enhance Per Channel Contrast, or Monochromatic Contrast.
These work nicely on a contrasting image that has good punch. But the important choice here is Snap Neutral Midtones. When you choose this, you’ll notice that color cast issues tend to be cleaned up and it just does a great job. In this case, it evaluated each channel separately, red, green, and blue. If I click OK, come over here and look at the curves, you’ll see that the blue channel lifted while red and green are actually pressed down. And what that did was balanced out the image, finding the nice neutral grays, and removing some of the white balance issues, and lighting issues that were caused in this photo from the way that it was shot, and the way that the sun was positioned.
This is just a simple, easy way to fix issues and it all ties to the Curves adjustment. Rather than doing it manually, though, just Option or Alt click on the word Auto and it’s very easy to fix color cast.