Correcting a Color Cast in Photoshop

There are many ways to correct a color cast in Photoshop. Generally speaking they fall into three broad categories - automatic/preset, subjective and analytical. I will be describing some of the more popular methods and where they may be used to maximum benefit in this and future posts, .

The first and the easiest is Automatic method. In Photoshop there are several places you can peform an automatic color adjustment. From the top menu you can select Image-Auto Color to make a reasonable guess at what a neutral color balance looks like. In general, this works pretty well in many, but not all, circumstances.

You can always go to auto settings in either the Image-Adjustment-Curves or Levels. Each has an Auto button which will adjust color, contrast, black and white levels, and brightness - all at the same time. The results are often quite good in many situations, and if you are in a hurry this often works well enough.

The next method is a bit more accurate, and is one of my favorites. It starts by making a duplicate of the image by selecting Image-Duplicate from the menu.

This will create a duplicate of your background image, and both are "pinned" to the desktop area in Photoshop. In order to carry out the next step, you will have to unpin the copy you just made. With the copy selected, left click in the top information area for the copy and drag the image away from its "pinning,"

This will create a floating window for the copied image. With the copy still selected, apply Filter-Blur-Average.

The copy becomes an image that averages all of the color values in your image.

If the blurred image is anything but neutral gray, as in the frame above, you have a color cast in your original image. You have just created the reference layer that you will use in the next step.

Select the ORIGINAL image and create a duplicate Background Layer by right clicking on the Background Layer in the Layer palette, and selecting Duplicate Layer. With the Duplicate Layer selected use the menu to select Image-Adjustments-Levels. (you can also use Curves if you prefer). Click on the middle eyedropper, and use it to sample the BLURRED image.

 The minute you click in the copied image the color balance in the original will automatically remove the cast.

At this point the blurred reference image is no longer needed and can be deleted.  By making the adjustment on a copy of the Background Copy, you can vary the opacity of that layer to adjust the amount of correction. In this case, the original image had a warm cast. So adjusting the opacity slider of the Background Copy layer to reveal more of the underlying image and its color cast. To my eye, the neutral balance was a bit cold, so I adjusted the opacity to 62% to produce a slightly warmer image. This is an important benefit of working on a copied layer- the correction is non-destructive and easy to adjust and/or undo.

You can turn off layer visibility of the Background copy layer by clicking in the "eye" icon to the left of the layer's thumbnail in the Layers palette to compare to the original.

If all is good, you can right click on the Background layer and select Flatten to finish.

This seems like a lot of steps to follow, but in practice you can complete this correction about 90 seconds or less. I will be detailing other color correction methods in upcoming posts, so be sure to stop by.