Open a new document in photoshop sizing:
Select the gradient tool.
Make sure the colors are set to this:
Use the following settings for the gradient tool:
Create a gradient by dragging from the top left corner to the bottom right corner:
Now, start in the BOTTOM RIGHT corner, and create the gradients from bottom right to top left corner. Only pull about a ΒΌ inch away from each other. You’ll have this:
Go to Image > Adjustments > Hue Saturation…
Use the following settings:
You will have this:
