Gradient?s parameters:

Create Futuristic Art Design Desktop Wallpaper in Photoshop CS

Select another tool now to represent a vertical line of black color situated in the central part of the picture.

Create Futuristic Art Design Desktop Wallpaper in Photoshop CS

The next instrument
will be helpful in representing the next layer:

Create Futuristic Art Design Desktop Wallpaper in Photoshop CS

Blending Options-Gradient Overlay

Create Futuristic Art Design Desktop Wallpaper in Photoshop CS

Gradient?s parameters:

Create Futuristic Art Design Desktop Wallpaper in Photoshop CS