Dodge & Burn discoloration

In order to make an objective comparison, one image was placed on the other, the layers aligned and a Lab Color reading was made of the identical area in each image. It revealed that the Lightness in the two images varied materially with the right image 8 points darker (on a scale from 0/black to 100/white) in tone.

The result shows thess samples are not a reliable guide for a comparison of the two techniques.

Once the two L (Lightness) values are within a point, the color values can be objectively compared to learn which of the two samples is closer to zero, indicating its greater shift toward gray. 

(Also, superimposing the images and clicking on the top layer eye revealed a significant differnce in the retouched areas)

Sometimes using such techniques I get to a point which I need to creat a flat Layer on top of my working: shift+alt+Cmd/ctrl+ E and maybe use a lightened Levels Layer, Invert it cmd/ctrl+I and then with a soft brush with a low opacity paint the area you want to lighten:

  I hope this helps,

Sim

If you are working in CMYK, it may give you some odd results. The best way is to work in RGB using the layer in Overlay mode, not Soft Light.

You could try the same technique in Lab mode