Steps: Select Mixer Brush Tool from Tools Panel under Brush Tool. Control Panel Settings: Use Clean Brush Make sure load brush after every stroke is not checked Use Custom Brush All Values of Wet,Mix,Load,Flow are below 15% Wet: 10% Mix: 12% Load: 8% Flow: 12% With all above settings done use the brush on the picture. Make sure not to mix up dark areas with bright areas and vise-versa. Please Watch Above Video for Detailed Explanation of the Tool.