Open a new file having
675x400 px and
72 dpi painted in black.
After that take the next instrument
and represent the lowest layer reserved for the site’s header. Apply the following instrument
to stretch out the upper part to the right side.
Blending Options-Gradient Overlay
Gradient's parameters: 
Copy this new made layer 2 times. The first copy should be minimized with
Free Transform option, move off the effects from it and change its color into another one –
330002.
on the layers.
The second copy must be minimized too, by using the same
Free Transform option and the color of the copy should be changed too into
810100.
