Page 130 - Photoshop for Lightroom Users – Scott Kelby 2nd Edition

Step 12:
Next, we’re going to change this layer’s blend mode to one that will let the color be transparent rather than a solid fill that covers our subject. So, choose
Color from the blend mode pop-up menu near the top left of the Layers panel (as seen here). This makes the blue fill see-through and now it’s more of a
tint. Of course, now she looks monochromatic and kind of blue, but it’s a step in the right direction (and we’ll adjust that in the next step).