Setting the Image's White Point
Setting the white point is 80% of proper color correction. The white point setting neutralizes the color and adjusts the image's tonal range to the white point of the printer/media combination.
Make sure the info Palette is visible on your screen. If it is not visible, select Window, Info.
Black Point moved to show highlights
Determining the Image's White Point
While still in an Adjustment Layer Curves Dialog Box, make sure the value readout is set to Ink Percentage. Drag the Black Point to the left until only the lightest areas in the image are visible. Make sure the Preview box is checked. This should help you visualize the highlight areas. Pick a white point that is neutral and not a spectral highlight. Spectral highlights are direct reflections of light sources. You can hover the cursor over parts of the image and compare the value readouts in the Info Palette. For more information on selecting white points see White Point Parameters.
Once you have determined the area for your white point, move the Black Point back to the far right.
Proper White Point Selection
Setting the White Point in the Image
Now click on the White Point Eyedropper and use it to select the white point area you have determined.
You may see the color shift when you make the selection with the eyedropper. This will work as long as you selected a neutral area and an appropriate highlight tone.
Click OK and the White Point is set.