Go to image adjustments and levels. Mess around with the levels until you get a dark look.
step 3 of 4
ADD THE RAIN and Lens Flare
Add a new Layer
Filter > Noise > Add Noise (Settings: 81.17%, Gaussian, Monochromatic)
Filter > Blur > Motion Blur
(Settings: -47 degree angle, Distance 24 pixels)
Image > Image Adjustments > Levels
(Input: 201; 1.00; 255)
Go to layer palette and change blending mode to Screen.
Render>Lens Flare
step 4 of 4
ADD A RAINBOW
1) Open the gardiant tool
2) Select transparent rainbow
3)Adjust the settings
4)Choose the radial gardiant on toolbar and draw a line
5) Filter>Distort>Polar Coordinates
6) Erase any unwanted parts.