Step 4-
Adjust Color With Curves
Finish off the tonal adjustments by correcting the color balance with the Curves command. In this case, I wanted to remove that greenish cast from the image.
Select Image>Adjust>Curves and click on the Channel pop-up menu and select the green channel. Click in the middle of the slope and drag down to lower the curve slightly. I also selected the Blue channel and lowered the blue curve, adding a bit of yellow to the image.
The result is shown at the left. Compare it with the original image to see how far we've come...
