Today’s Question: I’m looking for a tutorial that you did on removing what I’ll call a color cast from a portion of a picture. What I remember was a horse in a field with a partial greenish color cast caused by vegetation that was in the way when the picture was taken. Do you happen to remember where I may have seen this?
Tim’s Quick Answer: I don’t recall where that lesson may have been published, but it is a technique I have taught at a variety of workshops. The basic process involves painting with the desired color on a new layer in Photoshop, employing the Color blend mode.
More Detail: The first step is to add a new empty image layer directly above the Background image layer. To do so, first click on the thumbnail for the Background image layer. Then click the “Create a New Layer” button (the blank sheet of paper icon) at the bottom of the Layers panel.
To help stay organized I recommend renaming the new layer to something like “Color Fix”. To rename, simply double-click on the name of the layer, type a new name, and press Enter/Return on the keyboard to apply the change.
Next, change the blend mode for this new layer to Color. The default blend mode is Normal, which you’ll see reflected on the popup near the top-left of the Layers panel. Click that popup and choose Color.
You can now choose the Brush tool, and configure the tool to use a soft-edged brush (a low Hardness setting). I generally use a simple round brush, but you can use different shapes if it is helpful for your painting.
To select the color you want to paint with, hold the Alt key on Windows or the Option key on Macintosh and click within the image to select the desired color. For example, one of the images I have used to demonstrate this technique featured a horse with some green foliage in the foreground causing a color cast. In this situation I would hold the Alt/Option key while clicking on an appropriate color from the horse.
With the desired color selected, you can now paint in the area of the image that exhibits the problematic color cast. Note that to produce the best result you’ll generally need to sample a variety of different colors from the image while painting.
For example, if the horse in my sample image was brown, there would actually be many different shades of brown found within the horse. Therefore, I couldn’t simply choose a single shade of brown and paint over the entire area requiring color correction. Instead, I would sample various different shades of brown as I was working to resolve the color cast.
This technique is quite simple to implement, but can help you produce excellent results even with complicated color problems in the image. In effect, you are retaining all of the underlying texture while only altering the actual color appearance of the image, thanks to the Color blend mode.