Run Adobe Photoshop and click the “File” menu, and select “Open,” to open the file in Photoshop which you want to change. A new dialog box will appear, asking you about the location of the file that you want to use. Click the file to make it highlighted and then click “Open”.
From the “Image” drop-down menu, move your pointer to the "Adjustments" option, and a sub-menu will appear on your screen. From the sub-menu, click the "Replace Color" option. The "Replace Color" dialog option will now appear on your screen.
Now click on the color within your image, which you want to be replaced with another color. Your cursor will automatically be changed to eyedropper, which you will use to pick up the specific color. In the "Replace Color" dialog box, you will see “Fuzziness” option. You can use it to increase or decrease the fuzziness level of the chosen color.
If you increase the fuzziness level, more color level will be picked up by the image. The opposite will happen if you decrease the level of fuzziness.
At the bottom of the “Replace Color” dialog box, click the color box, which will open the “Select target color” dialog box to select the color which you want to use. You can choose from the list of colors available, or you can choose your custom color.
Click “OK” on the “Select target color” dialog box. The dialog will close now. Once again, click OK to close the “Replace color” box. You will now see a change in the color which you selected.
If you feel that the changes you made are not good, then you have the option to readjust the color by following the same process.