Photoshop :: Neutralizing Color Cast With Photo Filters?

I am learning to neutralize color casts in PS6, and one way I found was through this website:  [URL] ..... which proports to teach Photoshop.
 
In using their examples, in step 1 new adj layer, pick photo filter, fine.

Step 2 it says to click on color, which opens up the color picker dialogue box, and move cursor, which turns into eyedropper over the color you want to change and click on it. It is supposed to sample the color  and change the color in the color picker dialogue box.
 
When I click on the color, what comes up in the color picker window is WHITE (for new color), split with the original color of the filter. I cannot get it to come up the color I am picking. I cannot get it to come up without the split color in the box. Even if I change it to only use Gamut color, I still get a split box with white as my picked color.
 
When I use'command-click' on the color I want to sample, it changes the color in the image, instead of just sampling it for the (new) color in the color picker, so I it changes the original color in the image and I cannot use the information.
 
When I don't use a New Adj layer and just do it on the image, itself, it works.