Is there a standard colour code for wire-nuts or does it depend on the manufacturer?

I know Greenies are used for ground wires (with the hole on top for a pigtail).

The blue ones I've come across with, I use to temporarily splice #18 zip cord while I'm fixing a radio and need to hotwire the left-over stump of power cord.

It seems like that 2 or three #18s is the most the blue ones can handle. Ditto some gray ones that seem even smaller (which is what I'm currently using for that type of work).

I've seen orange ones....and yellow ones - the yellow are bigger than the orange, though.

I used a yellow one to replace a ceramic one in an electric menorah. It's holding 9 #18 wires!! Was the only thing that I could find that would hold all those wires securely. Just in case I also wrapped it in electrician's tape (is it made with real electricians? [Linked Image]).

And then I've run across some huge BLACK ones...made by Eagle Electric. These are old, though....

I've never been able to understand the conductor combination charts on the back of the bags...since sometimes the combinations they state are not quite what I'm doing (for example what about three #14s? What do you use for that? It doesn't mention it...but it does mention two #14s and a #16.

Anyone know of a chart on-line that I can print out or do I write to the manufacturers?

As far as brand goes....I don't really pay attention.

All I look for is that they have the little metal spring inside and that the critters are UL/CSA listed. They're IDEAL or Gardner-Bender.

I've noticed that the ones packaged by General Electric are made by IDEAL.

P.S. I always tape up my wirenuts if they're going to be used in permanent installations after I make sure the nut is firmly hand-tightened. I think you have more control and less chance of stripping the nut or snapping off the wire if you handtighten the nut instead of using a nut-driver. And I always pre-twist solid conductors.