Lighting Effects - The Photoshop: Professional Retouching and Compositing Tips, Tricks, and Techniques - page 197

Figure 3.40
2. To choose a suitable blue, I click the foreground color in the toolbar to open the
Color Picker, and I set the RGB values to R: 11; G: 53; B: 74. Click OK.
Note
We need to choose a darker color than what we expect to see in the final image.
This is because of how the blend mode we'll be using affects the result.
3. With a soft-edged brush, paint on your image where you want the reflected light to
appear.
4. Change the blend mode of the blue light layer to Color Dodge.
5. Press Command/Ctrl+J to create copy of the blue light layer, and do this several
more times until you have multiple copies in the layer stack ( Figure 3.41 ). This
brightens the blue light considerably ( Figure 3.42 ) .