SETP 1:You can do this on any resolution,I'm doing this on 1600x1200 resolution.first goto Filters>Render>clouds.(make sure you have foreground and background colors as black and white or else you well get clouds in different colors which we don't require.)


























STEP 2:Now go to Filters>Fibers.and small Fibers window opens as shown in below image change the settings to variance=12.0 and strength=26.0



















































STEP 3:Go to Filters>Blur>Motion Blur.A small window of Motion Blur opens as in the image shown below. change the settings as Angle=90' and Distance=999.click OK.and now press CTRL+F 5 to 6 times.

















































STEP 4:Create a NEW LAYER by pressing CTRL+N.Name it as Spectrum Layer click OK.after this select Gradient tool(shortcut key G) and change the gradient style to spectrum as shown in the image























STEP 5: In the Layers pellete change the blending mode of the spectrum Layer to Overlay as show in the below image. you are done. your own spectral wallpaper.if you want you can even add text to it or leave it like that.
























FINAL RESULT:



















if you need text tutorial as shown in the preview then comment in this. ill post it.