The RGB LED strips are using a controller chip called WS2811. This chip uses just a single data line (wire) to receive data from a microcontroller. “Timing is everything”, then this chip measure how much time the data line signal is high or low to understand what is 0 and what is 1.
The datasheet can be download from here:
Other interesting posts about these LED strips:
Using an iMX233-OLinuXino-NANO board to control WS2811 LED strip using LCD interface:
Also take a look at this nice project using these LED stripes:
Update: This is a nice post about WS2812 explaining more details about how it works:
Update2: He improved his code: https://github.com/cpldcpu/light_ws2812/