LED RGB strip lights can be connected at length with by using this 16 AWG UL listed wire. Use this with the RGB Solderless connector by butt splicing or using electrical tape to secure the lines together.
But wait, I am confused!? Which RGB LED strip light wire do I need? The 22 or the 16? These numbers correspong the the wire gauge, or, thickness of the wire. When putting 12v or 24v of electricity through a wire, the current will get weaker as it travels through the line. If you have a long run, you may get what is called 'voltage drop', meaning, that 12v you put into the wire may only a fraction of that once it reaches the end, meaning a lot less brightness in your lights, or not enough power to light them at all.
OK, so back to the numbers. Thicker wires enable the electricity to travel longer distances. Here is a page on voltage drop - http://www.flexfireleds.com/led-strip-light-voltage-drop-what-is-voltage-drop/
For short runs between RGB LED strips or from the controller to the lights, the 22 AWG RGB strip light extra wire will work
For longer runs, or if you are putting more than 4 amps through the line, use the 16 gauge. (You are on the correct page)