Begin by filling a blank canvas with 100% Black/40% Cyan. Go to Filter>Noise>Add Noise, applying an amount of 20%, set to Gaussian with the Monochromatic box activated, so the noise is black and white. Duplicate this layer and hit Cmd/Ctrl+T. Transform the layer’s size by four times so the noise looks more like small stars. Set the blending mode to Screen.
Add a new layer; set your Background colour as black and Foreground as a bright turquoise. Next, go to Filter>Render>Clouds, then repeat but this time adding a Difference Clouds filter to the layer. Press Cmd/Ctrl+F to add this filter effect several times. Set the blending mode to Screen. Double-click on this layer to bring up the Layer Style options and find the This Layer slider at the bottom of the palette. Opt/Alt-drag the left black slider so it divides into two and tweak these values until satisfied.
Repeat the Clouds and Difference Clouds process on a new layer with a bright purple tone. Set this layer to Hue and double-click. Repeat the This Layer slider step. Now group the two coloured layers and press Cmd/Ctrl+T, increasing the size of this group until you focus in on a section which looks like deep space.
