*You can use the Star Background for this…
Open the Star Background you created.
Create a new layer and name it Colors.
Select the marquee selection tool.
Make a selection on the top half of the document.
Select the gradient tool from the tools palette.
Use this gradient:
Use the following settings:
Start the gradient in the bottom lefthand corner and take it to the top righthand corner diagonally.
You will have this:
Press Command D to deselect.
Set the layer to Linear Light at 40% Opacity.
Select the Eraser tool.
Use a large soft edge brush and bring to opacity of the brush down to 50%. (You may want to toggle the opacity levels to get a more realistic result)
Erase the bottom edges lightly while changing the opacity levels frequently to achieve the desired result:
