Is there an unwanted color cast spoiling your photo? Correcting this is really simple when you use the curves tool, as demonstrated by PiXimperfect in this 7-minute tutorial.
To do this, you’re going to be telling Photoshop exactly what part of your photo should be gray. Or, to be more specific, 50% gray. The software will then adjust that specific pixel to 50% gray, and correct the rest of the image to suit.
First, create a curves adjustment layer. Then select the middle eye-dropper tool from the sidebar of the curves panel.
Now just click on areas which should be gray, but may have a weird color cast instead, and you’ll see your photo improve immensely.
But what if no part of your photo has an obvious area that should be 50% gray? In this case, you need to find the part of the image that is as close to 50% gray as possible.
Luckily, this is really simple too. Create a solid color adjustment layer of 50% gray by pressing “shift + backspace” on your keyboard, and select 50% gray from the dropdown. Voila!
Next, with that layer highlighted, choose the “Difference” blend mode. Areas of the image that now appear black are closest, or exactly, 50% gray. The darker the areas of the image, the closer they are to true 50% gray.
Now you’ve found the area, delete that color adjustment layer and select the spot you found, with the eye-dropper from the beginning of the tutorial, for proper color correction.
Check out the full video above to see exactly how this technique is done. You can also find more tutorials by subscribing to PiXimperfect on YouTube.