Replacing colors in an image

With the Replace Color command, you can create temporary masks based on specific colors and then replace these colors. (A mask isolates an area of an image, so that changes affect just the selected area and not the rest of the image.) The Replace Color dialog box contains options for adjusting the hue, saturation, and lightness components of the selection: Hue is color, saturation is the purity of the color, and lightness is how much white or black is in the image.

You’ll use the Replace Color command to change the color of the wall at the top of the image. The Replace Color command is not available in ImageReady.

1.	Select the rectangular marquee tool (), and draw a selection border around the blue wall at the top of the image. Don’t worry about making a perfect selection, but be sure to include all of the blue wall.
2.	Choose Image > Adjustments > Replace Color to open the Replace Color dialog box. By default, the Selection area of the Replace Color dialog box displays a black rectangle, representing the current selection. Notice the three eyedropper tools in the Replace Color dialog box. One selects a single color; another selects additional colors and adds them to the color selection; the third selects colors that it removes from a selection. A. Single-color eyedropper tool B. Eyedropper plus tool C. Eyedropper minus tool
3.	Select the first (single-color) eyedropper tool () in the Replace Color dialog box and click anywhere in the blue-wall area of the image window to select all of the area with that color.
4.	In the Replace Color dialog box, select the eyedropper-plus tool (), and drag over the other areas of the blue wall until the entire wall shape is highlighted in white in the dialog box.
5.	Adjust the tolerance level of the mask by dragging the Fuzziness slider or typing 80. Fuzziness controls the degree to which related colors are included in the mask.
6.	If there are any white areas of the mask display in the dialog box that are not part of the wall, select the eyedropper-minus tool () and click in the black area around the selection in the Replace Color dialog box to remove most of the white. (It’s OK if a few pixels in the shadowed window inset remain in the selection.)
7.	In the Transform area of the Replace Color dialog box, drag the Hue slider to –40, the Saturation slider to –45, and the Lightness slider to 0. As you change the values, the color of the wall changes in hue, saturation, and lightness, so that the wall is now a slaty green color.
8.	Click OK to apply the changes.
9.	Choose Select > Deselect, and then choose File > Save.