Step 1. Create a new document. Double-click on the background layer to open the layer styles. Select Gradient overlay (gradient overlay) and use black and navy. Select a radial gradient style.
Step 2. Create a new layer and fill it with black.
Step 3. Select the primary color black, and the background gray. Apply Filters> Render> Fibers (filter> rendering> fibers). Set the deviation to 36, and the intensity to 1.
Step 4. Apply Filters> Blur> Motion Blur (filter> blur> motion blur). I set the offset to 999, this is the maximum value, but you can try a different value. For the angle I used the value of 90 º.
Step 5. Double-click on this layer to open the layer styles. Select Gradient overlay (gradient overlay). Use the colors of the rainbow: purple, blue, green, yellow and red.
Step 6. Using Lasso Tool (lasso) (L), create any selection, as I did. Feather pen 30px. After that, go to Layer> Layer Mask> Reveal Selection (layer> layer mask> show selected area).
This is a very simple but cool effect. You can use it for website titles, disc covers, in general for what you want. I just created beautiful wallpapers for my blog. Again, there are many ways to achieve the same result, perhaps using other filters and settings. It’s all about playing with the tool. In addition, if you are using the CS3 version of Photoshop, you can use smart filters to use different values and you will see the effect, do not focus on this version of the lesson.