Don't get me wrong; I love the Adjustments Panel but I would like one little enhancement to the Color Balance Tab. In addition to the three Tone variants (Shadows, Midtones,and Highlights) could there be a button that allows the user to have the Color Balance adjustments applied uniformly to the entire image rather than having to go through each of the three Tone ranges separately?
I fully appreciate that one may not want to have the same setting applied through all three Tone ranges but one should be able to apply an overall Color Balance setting and then go into each of the three tone ranges and adjust the sliders as desired. I think this would be easier than what I do now which is to go through each Tone range trying to apply more-or-less the same adjustments relying on my memory as best I can.
There are already many different ways to do what you want.
One, try Selective Color - choose Neutrals from the drop down, and 'absolute'. Unfortunately in this usage its bad terminology, 'Neutrals' doesn't really mean neutral (grays) at all it means VERY broad mid-tones. It applies a more overall adjustment.
Alternatively just going into Levels and playing around with the midpoint sliders might give you want you want. Colored overlays, Curves, Hue/sat will also if properly used do this. Remember adjustment layers can be blended with 'Color' blend mode if you see tonality shifting too much. Many ways to skin a cat.