1. At first you should create a new document, 500×500 pixels, transparent background, RGB Color.
2. Then you should put FF0000 as the foreground color and fill the layer (alt + backspace)
3. Filter -> Render -> Lighting Effects and  you can use the settings below

Photoshop Lighting Effect properties.
4. After that you should create new layer and hit D for defaults
5. Filter -> Render -> Clouds
6. Filter -> Render -> Different Clouds, then you must do it 6 times
7. Image -> Adjust -> Auto Levels
8. Ctrl + U: use the settings below:

Hue/Saturation settings.
9.  Then you should duplicate the layer
10. Filter -> Blur -> Radical Blur -> Amount: 100, Blur Method: Zoom, Quality: Best
11. On the original layer, do filter -> render -> lighting effects and use the settings:

Photoshop Lighting Effect properties.
12. On the topmost layer, you can set the blending mode to Lighten. (Double click layer to bring up blending options)
13. On the second layer, you should set the blending mode to Lighten.