What do the colours mean?

Using Arduino Motors, Mechanics, Power and CNC
1

I have bought this servo:

http://www.aliexpress.com/store/product/keyes-Smart-car-XY-axis-PTZ/320981_598719649.html

It has three wires yellow, red and brown. The yellow one has a m on it. Which is voltage, ground and the other one?

2

It seems that they're standard.