Color Replacement Tool

The Color Replacement tool offers a much more hands-on approach to replacing colors in an image. It allows you to replace an area of color with the current foreground color by painting over it with a brush. What’s even better is that you don’t have to worry about being extra precise. Photoshop replaces only those colors that you mouse over with the brush cursor’s center crosshair. One drawback to using the Color Replacement tool is that you cannot work with it nondestructively as you can with Hue/Saturation  adjustment layers. The best you can do is use it on a duplicate of the image, keeping an untouched original in the Layers palette or in a separate document. However, for quick and easy color changes, the Color Replacement tool can still be useful. You can access the Color Replacement tool by clicking and holding the currently visible Brush icon in the Tools palette and selecting Color Replacement Tool from the pop-up menu that appears. You can also toggle between the Brush tool, Pencil tool, and Color Replacement tool by pressing Shift+B or by Option/Alt+clicking on the forefront icon in the palette.

With the exception of the Mode menu, the Options palette controls for the Color Replacement tool are exactly the same as those for the Background Eraser. Use these controls to indicate which areas should change and which ones should be ignored as you paint with the brush. Choose an option from the Mode menu to indicate how you’d like the foreground color applied wherever you paint:
Hue changes the basic color without changing the brightness or saturation. This is the mode to use for controlled recoloring.
Saturation makes the affected area as colorful (or saturated) as the chosen foreground color. It does not change the color or brightness of the area. Painting with a foreground color of black, white, or any shade of gray desaturates the affected area, converting it to black-and-white.
Color changes the basic color and saturation of the affected area, but not the brightness. Painting in this mode is like applying the Hue/Saturation Colorize option with a brush.
Luminosity changes the brightness (or luminosity) of the affected area to match the chosen foreground color. It does not allow you to shift colors.
For general recolorization, select a replacement color by using the Color Picker, set the Mode option to Hue, and keep the sampling option set to Continuous. After the proper Limits and Tolerance options are set, simply paint over the image area you’d like to recolor.