These Lights come with 3 wires. + and - like normal, and a third wire, when you run current as normal through the + and - wire you have the normal colour like Amber/Orange, Red. When you run current through the third wire the lights go to the Auxiliary Colour.
Auxiliary colours available are Purple, Green, Blue, Red, White and Blue USA stripes and White. White is normally used for extra reverse lighting.
Some of the lights do "stop, turn, tail" and reverse. This means the one light can have the function of Tail (light red when the lights are on normally), Stop (Bright Red when you put on the brake), Turn (flashing red when you indicate - red not amber), and reverse 9bright white when you put the vehicle into reverse.
Note all these colour changing lights are 12V only. If you have a 24V truck like a European truck you will need to fit reducers.
While the lights give you a lot of options, you must ensure you always meet the NZ lighting requirements when on highway. Knowing and meeting these is your responsibility.