Despite our best efforts as photographers to get everything perfect in the camera, at times you’ll find an unwanted element ended up within the frame. In some cases you might simply move on to a different image if the distracting element is problematic enough. Otherwise you would probably crop the image to cut out the problem area or use a combination of the Clone Stamp and Healing Brush tools to eliminate the unwanted element.

There’s another trick that can be incredibly helpful when the problem is what I refer to as “color contamination” in the photo. This occurs when an object protrudes into the frame, but is rendered completely out of focus (generally because the object is very close to the lens). The result is a color wash that is translucent, allowing you to see the textures behind that object. In other words, all you really need to eliminate is the color--not the texture and detail--in the problem area of the image.

Of course, there are many other situations where the ability to correct color contamination without affecting tone or texture is helpful. I’ve used this technique to remove unwanted colors from lens flare, eliminate color halos found in many underwater photographs or caused by chromatic aberration, and many other situations where I want to change only the color in an area of a photograph. It can also be used for more creative applications, such as changing the color of objects in an image or hand-coloring an image that has been converted to grayscale via a Black & White adjustment layer.
To get started, go to the Layers panel and click on your Background image layer to make it active. Then click the Create a New Layer button (it has a blank sheet of paper icon) at the bottom of the Layers panel. It is a good idea to rename this layer so you’ll know why it is there, so double-click the name of the new layer on the Layers panel, type a new name, and press Enter/Return.
Next is the little bit of magic that is the key to this technique. Choose the Color blend mode from the popup at the top-left of the Layers panel. By choosing this blend mode for the layer, anything painted onto this layer will only affect the color, but not the tone or texture, of the underlying image.

When you choose the Color blend mode you might notice there are also other blend modes in the same section on the list that relate to other properties of color. These are Hue, Saturation, and Luminosity. In this context Color is actually a combination of Hue and Saturation. In most cases that’s the best choice, but sometimes you might get better results by using the Hue blend mode, which will change the actual color of the area you’re correcting without altering the saturation of that area. Color is usually the best blend mode for this technique, but if it doesn’t seem to be working well on a particular image give Hue a try as well.
With the Layers panel properly configured, you’re ready to get to work correcting the image. Choose the Brush tool from the Tools panel, and choose a soft-edged brush on the Options bar. Make sure the Mode on the Options bar is set to Normal (the magic will be happening on the layer, so we want the brush to behave normally) and that the Opacity is at 100%. Then, hold the Alt/Option key to access the Eyedropper tool while still working with the Brush tool and click on an area of the image that contains a color appropriate to fix the problem area. This will set the foreground color to the color you clicked on.

At this point you’re ready to apply the fix. Simply paint within the image to start cleaning up the color contamination. Pay careful attention to the effect you’re having, selecting a new color from within the image whenever necessary to ensure the best (and most accurate) result possible.

If you’re careful about the choice of colors you select to paint with and do a precise job painting the correction, you should be able to produce excellent results. If for any reason you can’t find an appropriate color within the image, you can also click the color swatch for the foreground color on the Tools panel and choose any color you like from the Color Picker. Also, if the color correction works well but there are still variations in tonality caused by the unwanted element of the image, you may need to apply some slight dodging and burning to correct the tone.

This technique is quick and easy to apply, and I think you’ll discover it can be incredibly valuable in a wide variety of situations.

© Tim Grey {/rokaccess}