Question for the PS Guru's - Digital Grey Card Action Help!

If they look the same there must be something wrong with your monitor. My correction was made to show you how much yours is off from realistic color.

Making the action is quite easy, but even then a bit of user input would be necessary, and the action wouldn't be effective in correcting white balance. Almost no picture has a single, uniform light source, and one is lucky to have a true graypoint in a picture. The picture you've presented has 3 lightsources in it. The blueish ambient light, the yellow sunlight and the green hue by the leaves.

Again, you cannot demand a PC to be smart enough to use this info and do an automatic correction that is accurate enough to be pleasing.