changing the DOS background colour

The value DefaultColor controls the foreground and background colors used in command prompt windows. It has a default value of 0, for standard white text on a black background.
CHANGING DOS BACKGROUND
Open your registry (press win+r and type regedit , hit enter )
goto


[HKEY_CURRENT_USER\Software\Microsoft\Command Processor]

u'll find "DefaultColor"

You can replace it's value with a two-digit hexadecimal number, in which the first digit selects a background color and the second a foreground color. The hexadecimal codes are:

Hexadecimal value Color
0 Black
1 Blue
2 Green
3 Aqua
4 Red
5 Purple
6 Yellow
7 White
8 Gray
9 Light Blue
A Light Green
B Light Aqua
C Light Red
D Light Purple
E Light Yellow
F Bright White


A value of F0, for example, would give black text on a white background, and 1E would yield yellow text on a blue background.

The change should take effect the next time you open a console window.

another simple method 

1. Start Menu ---->All Proograme  --->Accessioies  --->comand prompt
2. or press win key + r then type cmd
3. then command prompt will open
4. then type color then number of color which is given above
5. ex:color 17