Open a blank document of 1280 x 1024px and fill it up with black color
Now Go to> Filter> Render> Clouds and apply clouds, before applying clouds filter, make sure you have selected default colors black and white
Now Go to Filter> Pixelate> Mosaic and adjust cell size according to your need
Now we will have something like that after applying above filter
Now to make our cell’s edges look more clear we will apply Reticulation, for this goto> Filter> Sketch> Reticulation and apply the following settings
now as you can see we have sharp cell edges with sharp colors
Now its time to add some glow to our cells, for this goto>Filter> Sketch> Photocopy and apply the given settings
Now you’ll have something like this
Now we have to invert its Colors by pressing Ctrl+I
its time to add some colors into our cells, for this Go to Image> Adjustments> Hue/Saturation or shortcut Ctrl+U and apply following settings or you can use your own colors.
now this is what we got after applying colors
Now we will add some perspective to our wallpaper, for this Press Ctrl+T and Select Perspective as shown
Now Make it look similar as i did below
Now create a new layer in the background and fill it with black to cover the transparency
Now open blending option of our Mosaic layer and apply outer glow to this layer with AD005E Color
We are Done…!