Epson 660 - Manual (Page 49)

To adjust the color balance, first, you select the channel you want to adjust, then drag the triangles under
the three color bars. You can also enter the desired values directly into the three entry boxes to the right
of the color bars to adjust the color balance.
For example, if the color of the brighter area in the original you scan appears to be bluish, you can first
choose Highlight as the channel, and then drag the triangle below Cyan-Red bar to the right, or drag the
triangle below the Yellow-Blue bar to the left to eliminate the bluish effect.
Default parameters as:
Item Range Default value
Color channel Mid-tone
Cyan and red -100~100 0
Magenta and
green
-100~100 0
Yellow and
blue
-100~100 0