Create a new layer on top of ‘background1’ with a new layer mask, naming it ‘background2’. Fill it with the colour #020317.
Select the Brush tool and, using a very large Soft Round Brush with 30% opacity, select the colour #1cif3c. Paint the central area of your canvas with this colour. Then create a layer mask at the centre of this painted area.
Now we’re going to create the sky. Create a new layer, naming it ‘background3’. Select the Rough Round Bristle brush in #003cff, setting the opacity to 8%, and paint in a soft centre to your canvas. Don’t worry if the changes you’re making don’t have much visible effect: you’ll see the benefit of these later.
Create another new layer, call it ‘background4’, and using the same brush and colour, paint in the top left-hand corner of the layer. Create a layer mask and soften the layer, this time using the Soft Round brush.