Retouching and restoring images : Replacing colors, gradients, or patterns
 
Replacing colors, gradients, or patterns
You can use the Color Replacer tool to replace one color in a selection or layer with another color. You can use brushstrokes to replace only those pixels that the brush touches, or you can replace all pixels of a certain color in a selection or layer.
You can set a tolerance value so that the Color Replacer tool changes within a given color value range. The Color Replacer tool also works with gradients and patterns.
You can also use the Flood Fill tool to replace all pixels of a certain color in a selection or a layer. For information about the differences between the Color Replacer tool and the Flood Fill tool, see Filling areas with colors, gradients, or patterns.
Why does nothing happen when I apply the Color Replacer tool?
You must select a foreground or background color that appears in the image. If there are no pixels that match your selected color, then no pixel colors are replaced.
For more information about picking a foreground or background color directly from the image, see Choosing colors from an image or the desktop.
To replace a color, gradient, or pattern
Edit workspace 
1 On the Tools toolbar, choose the Color Replacer tool .
2 Choose the material (color, gradient, or pattern) that you want to replace. Click the material to apply it as the Foreground/Stroke, or right-click the material to apply it as the Background/Fill.
3 Choose a material to use as a replacement material. The replacement material can be any material in the current image, or you can choose one from the Materials palette.
If the material you want to replace is the current Foreground/Stroke material, right-click the replacement material to set it as the Background/Fill.
If the material you want to replace is the current Background/Fill material, click the replacement material to set it as the Foreground/Stroke.
4 In the Tolerance box, set a value from 0 to 200 to specify how closely the replacement material should match the material you are replacing.
At lower Tolerance settings, only pixels with very similar colors are replaced; at higher settings, more pixels are replaced.
5 Position the cursor over the area of a selection or layer that contains the material you want to replace, and perform a task from the following table.
 
To
Do the following
Swap all occurrences of a background or foreground material
Double-click to swap the Background/Fill material with the Foreground/Stroke material; double-click the right mouse button to swap the Foreground/Stroke material with the Background/Fill material.
Replace all matching pixels with the current Foreground/Stroke material
On the Tool Options palette, click the Replace all pixels button .
Replace materials by using brushstrokes rather than replacing all pixels in the layer
On the Tool Options palette, choose the brush tip, size, opacity, and other options. Drag in the image to replace the Background/Fill material with the Foreground/Stroke material; drag with the right mouse button to replace the Foreground/Stroke material with the Background/Fill material.
To limit changes to a specific area, make a selection in the image before using the Color Replacer tool.