Epson Perfection V500 - Manual (Page 124)

You can also use the cells to the right of the adjustment area to change the
brightness, if necessary.
If you want to continue adjusting the color, repeat step 4.
If you want to save the color for future scans, click the Save button. The color
appears in the save area.
Note:
To load a previously saved color, select the color and click the Apply to
Palette button.
When you are finished adjusting the color, click the Close button to return to the Epson
Scan window.
For further details on using the Color Palette feature, click the Help button.
Applying a Color to an Image
If necessary, click the Preview button to preview your image. Then click the Color
Palette button.
The Color Palette window appears.