This tool is a very handy tool for replacing color in a photo inside of Photoshop. It is found behind the brush tool and goes as far back as CS3. This sort of works like making a new layer and setting it to color in the layers panel. That is an old trick from before the invention of this tool. The image used for this tutorial can be found on Stock.xchange, taken by Billy Frank Alexander. If you would like to try this out on the same image, it can be found here.
There are several aspects to this tool that make it handy, and the different settings allow you to be able to do different things. The first is mode. Mode decides what will be effected; Hue, Color, Luminosity, and Saturation.
Hue- When using Hue, you will be painting the color of the object to the same hue value as your foreground color. This means that if you have a pale greenish leaf, when you paint with a strong red, the leaf will actually be turned to a pale pinkish hue.
Saturation- When painting with Saturation, the object that you are painting will be converted to match the same saturation value as the foreground color that you have chosen. In the example, the change is subtle, but this can make a difference when you need a certain level of control in your saturation level of an object’s color.
Color- This mode actually replaces the color of the object with the foreground color. This option has a lot more strength to it, but it doesn’t completely turn it the bright red that we have selected.
Luminosity- I am not sure why someone would want to do this, but this removes the luminosity of the object and actually makes it fairly dull and flat. When using the red, it made the image dark. When I held option and clicked to sample a color from the leaf, it made any color close to that flat and lose dimension. It also doesn’t deal with edges well, going outside the boundaries of the leaf image.
The next setting is the Sampling setting. This setting determines where you get your sample to replace from. Contiguous means that it will replace the entire area that you are dragging over. If you choose Once it will only replace the color that you option clicked on. Background only affects the same color that you have selected as your background color.
The Limits setting determines where the color stops replacing. Contiguous means that it won’t go past where the color drastically changes. Colors that are really close in nature will be included. This is of course affected by the Tolerance setting, which determines how many shades up and down will be included in being changed.
A good example of using this tool would be to take a leaf that is not quite the right color for a fall image, and using the color replacement tool set to color mode to color it a medium orange. This gives it a fall look, and it really handy. You could apply this to many different image needs. This allows you to paint in the color replacement, rather than trying to use a mask, or adjustment layer with a mask. it allows you more manual control.