color sets cmd.exe's console's foreground and background color using two (hexadecimal) digits in the range from 0 … f.
The first digit specifies the background color, the second one the foreground color: the range 8…F repeats the color of the range 0…7, yet lighter or brighter:
0 / 8
black / grey
1 / 9
blue
2 / A
green
3 / B
aqua
4 / C
red
5 / D
purple
6 / E
yellow
7 / F
white
Thus, the following command sets the background to the dark version of blue and the foreground to the light version of yellow:
color 1e
color without arguments resets the colors to its defaults.
color is affected by whether command extensions are enabled or disabled.