Here ia a nice portable tool to generate random wallpaper with color gradients and display it on your desktop with just one click!

Randomize assigns random colors to all four corners.
 
Set as Wallpaper – saves the picture to My Pictures\GradientWallpaper.bmp and sets the Windows Desktop wallpaper to this file. It will overwrite the file if it exists.
 
Save colors to text file – appends the RGB values of the current colors to the “colors.txt” log file in the program’s directory, in case you liked the colors and want to save the colors, not the image.

You can also click on each of the four corners and pick any color yourself. There are a total of 79228162514264337593543950336 possible wallpapers that can be generated this way.

Home Page-MSDN | Download Page-Codeplex.

You might also want to check out Wallpaper Manager for Windows from MSN.

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