Below is a simplified version of a system I'm working on. There's over 10 devices and they all come through the ammeter and split off into each device (only using 2 devices here for simplicity).

The current circuit has been wired where it's red wire all the way until the last device and then black wire to the negative side of the power supply.

What exactly would the correct wiring color be according to conventions? My temptation is to do Red -> Black -> Red -> Black -> Red ....

Current Wiring

  • \$\begingroup\$ Are you planning star or radial wiring or daisy chained for light or static loads . You want to avoid sharing dirty grounds. Colours look OK \$\endgroup\$ Commented Jan 10, 2020 at 21:49
  • \$\begingroup\$ @TonyStewartSunnyskyguyEE75 I had to look up the difference but I believe it would be a star (or ring if that's the same thing) ... as if the system is running off of a battery. \$\endgroup\$
    – fullyjosh
    Commented Jan 10, 2020 at 21:57

2 Answers 2


First, I would tend to switch the high side for various reasons.

The only convention I follow is to use "hot" colors for positive and "cold" colors for negative. And if there are only a positive rail and ground, use red and black for those.

So with your wiring I might use red (+12)->orange->blue->black (GND)

With the contacts on the high side red->orange->yellow->black

The color "hotness" changes where most of the voltage is dropped, across the loads.

Maybe there is some standard that calls this out for DC circuits.

  • \$\begingroup\$ Interesting...I've never heard that but maybe something to consider. Thanks! \$\endgroup\$
    – fullyjosh
    Commented Jan 10, 2020 at 21:58
  • \$\begingroup\$ For marine use, ABYC wants yellow for negative/ground to avoid confusion with AC Hot wires. \$\endgroup\$ Commented Jan 10, 2020 at 22:15
  • \$\begingroup\$ I like to use colors like grey or brown for negative voltages. And I often use green for ground if there are also 120 VAC connections, where I use the standard US custom of black and white. Usually my DC ground is also connected to chassis and earth, so green is consistent. \$\endgroup\$
    – PStechPaul
    Commented Dec 29, 2022 at 1:07
  • \$\begingroup\$ @PStechPaul I think green or green+yellow stripe should be reserved for earth. \$\endgroup\$ Commented Dec 29, 2022 at 2:20

I generally follow PC power supply convention - 12V is yellow, 5V is red, 3.3V is orange, GND is black. Make sure you don't accidentally follow your local HVAC convention (Brown, Blue +Green yellow, or black,white +green).

  • \$\begingroup\$ Yellow tells me overdrive… \$\endgroup\$
    – Solar Mike
    Commented Dec 29, 2022 at 0:13

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