Only three wires will be used. The red wire does not connect to the Arduino.
The red wire does not connect to the Arduino. You can trim this wire from the mating connector or insulate it with tape or heat-shrink tube.
Even though we don't suggest it, you can use an Arduino Mega, connect Green to 52 (SPI Clock) and Yellow to 51 (SPI MOSI), red and blue are the same as above. With the Leonardo, unfortunately the SPI pins are on the 6 pin programming header in the center of the board, so its really not suggested.
The extra red and blue wires are for connecting power, but we’ll do this at the other end of the strand.