1.

This tutorial was written by "Good Christian"
Pastile ejaculare

(Create a new image).
Take pencil tool and draw a straight line of 1 pixel, then draw another 31 pixels lower
The color is 102/102/126

2.

Take the magic wand and select the part between the two lines.

3.

Set foreground color to 168/167/191 and background color to white.
Take gradient tool, hold shift, move from top to bottom and release your mouse .

4.

Deselect and make a new selection. Make it 3 pixels high and move it so you got the dark blue line and one light blue line above your selection.

(close up)