matching skin tones

Please post meaningful screenshots, the Properties Panel is clipped in this one. 

Have you looked at the actual Curves you created? Because you already appear to be causing clipping (the regions where the red and green curves intersect with the top of the grid).

What exactly are you trying to do? 

If you want to match one part to another you may have to employ Layer Masks to limit an Adjustment Layer’s effect to the intended area. 

Use the Color sampler tool, and add a point to each of the coloured areas.

You'll see the values in the Info panel, so drag that to a convenient place.

Use the Quick Selection tool to select the color on the left (assuming that is the one you need to adjust).

Withg that selection in place, add a Hue/Saturation adjustment layer.  It's layer mask will reflect the selection you made, so the edit will only affect the clour on the left.

Use the Hue slider to get close to the right colour.  You'll also need to move the Lightness slider to the left to darken it.

As you make your adjustments

Watch the values in the Info panekl as you make the adjustments

(I'm cooking and something is burning so quick and dirty 

good luck