I am a complete newbie to Arduino and I just received an ARDX arduino starter kit (the one that comes in the transparent green case) I have been following the instructions for Circ-01 for the blinking led light but I am curious about the wires. In the breadboard instructional picture it shows a purple wire that is supposed to connect to pin 13 on the arduino. But the kit did not come with a purple wire, it only came with black, red, white, yellow, and green wires.

I also tried following a tutorial on YouTube and the guy in the video used a purple wire that he said was the led "cathode"

Can i substitute another wire for the purple and? Or did I receive an incomplete kit? I am very confused and the breadboard instruction picture is not very clear.

Thanks for any help!

  • Go buy some Quality Street. Eat one of the nice purple ones. Flatten out the wrapper. Look through it at a white wire. It now looks purple. The colour of wires makes absolutely no difference to a circuit - it is purely for humans to keep track of what is what.
    – Majenko
    Jun 6, 2016 at 22:01

1 Answer 1


Personally I like to try to use red wires for +5V, black or blue for ground, and yellow for data. However as Majenko said in a comment, the colour is irrelevant to the operation.

The usefulness of colour is just that if you stick to a system (like red for +5V and black for ground) then there is a visual check you make when connecting up a circuit, so you don't accidentally put things in backwards, like you might if every wire is yellow.

Also, if you run half-a-dozen wires from one place to another, using different colours is another way of making it easier to see you have connected the correct things together.

Having said all that, the colour does not otherwise affect things.


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