Using a Curves Layer to Remove Color Casts in Photoshop

It’s bound to happen sooner or later. You’re out shooting, and when you load the pictures onto your computer afterward and take a look, you find your subject has a less-than attractive color cast. A good example of this is when you’re shooting on a bright day in the park, and you find green casts under your subject’s chin and on the sides of their face from the reflection of the light off of the grass. well, friends and neighbors, there’s a fix for that, and all it takes is a simple curves adjustment layer!

This is the image we’re going to start with. It was destined for the bin, but then I realized it would make a great example for this guide. It was taken in the shade, with a background of harsh sun and green grass. Poor little dude is a bit green around the gills, but we can take care of that.

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We’ll start the process by going to Photoshop’s Layers palette. At the bottom of the palette is a row of icons. The round one is the add adjustments layer button. Click on that, and create a new Curves adjustment layer as shown below.

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When you create the new layer, you will automatically switch to the layer properties palette. I have that palette grouped together with my layers and history palettes, but yours might not necessarily be in the same place. In any case, we don’t want that just yet, so once the layer is created, go back to the layers palette, and you will see the new adjustment layer. On that new layer, the layer mask will be selected by default, but we want to select the layer itself by clicking on the layer thumbnail, as shown.

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Now that we have the adjustment layer selected, we need to go back to the layer properties palette. On this palette, double-click on the topmost of the three eyedropper tools on the left side of the palette as shown.

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Clicking the eyedropper opens the color picker palette. With this palette open, choose a good color in the image that represents what you want the color to look like in the area with the cast. In this case, I sampled an area on his cheek that looked like it was about right, and was free of the green cast that we want to dispose of.

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Once you’ve sampled the color you want, click OK on the color picker palette. When that box disappears, you will be presented with another box asking if you wish to set the target color as the default. Just click No.

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After you click No, the next thing you want to do is click on an area of the image that IS afflicted with the color cast you want to get rid off. In this case, I sampled an area on his left cheek.

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When you click to sample the color cast, the image will immediately change color. Depending on the color and the degree of cast, your image may just look a little weird, like my image, or it may look absolutely horrible. Either way, that’s okay. This layer is what will provide us the color to correct our color cast.

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Now go back to the layers palette. This time, we want to select the layer mask on our curves adjustment layer, as shown below. With the layer mask selected, press CTRL+I on your keyboard ( or Command+I if you’re on a Mac) to invert the layer mask. You’ll notice two things happen when you do that. One is that the image will revert to its previous appearance, and the second is that the layer mask icon on the layers palette turns black. What this means is that the color correction is now hidden by the mask. Now we have to selectively uncover that layer to correct our colors.

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To start fixing the colors in your image, you need to set up a brush to paint in the fix. You first need to select the brush tool (by clicking on the brush icon or pressing the B key). Then set your foreground color to white, choose a soft (0% hardness) brush, and set it to around 15% opacity.

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Once the brush settings are correct, adjust the brush to a size that is appropriate the the area you’re going to be correcting, and begin to brush over the area that you want to correct. You’ll see the color cast fading as you go over the afflicted areas. You can build up the new color by simply going over an area more than once. The shot below shows what it looks like after I’ve brushed over the skin to remove the green cast.

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The skin color on the sample image looks much better now, but the hair is still green. To correct that, I added a second curves adjustment layer just for the hair.

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Here’s the final result. You can see that most of the green is gone now, and he looks a lot more natural and a lot less nauseated.

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One final shot, just to give you a side by side comparison of before and after our corrections. You can also use this technique to help change or even out skin tones, change the colors of things in your photos, and a lot more. I hope you find this guide useful. I know learning this trick definitely eased the process of correcting colors for me.

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