Octaves have no color?
Suggestions past lavender
13a is neutral, and so purplish (much like 11a's lavender and the purple coming from equating rry1 and zzg3). Now there aren't many colours with a "th" in them, so I had to cheat a bit here. 13o is heather (I know it doesn't begin "th", but it'll have to do), 13u is thistle.
17a is close to ya, but slightly wider than yo and narrower than gu. Therefore, it needs colours that are slightly orange-yellow and slightly blue-green. 17o is sea, 17u is saffron.
19a is similar to 17a, and so needs similar colours. 19o is new leaf (probably should change to avoid clashing with nu, but I can't think of anything else), while 19u is nectarine. -- Jerdle (talk) 17:33, 20 October 2019 (UTC)
Subgroups that use non-primes?
How does color notation name subgroups that use non-primes like 2.9.21 if you don't have names like ya, za etc for non-primes? Would saying "wa 2nd plus zo 4th" be okay? IlL (talk) 05:29, 8 July 2020 (UTC)
Good question. I've struggled with this. Your approach seems promising! For 2.9.21 I would say "nowa plus wa 2nd plus zo 4th", to make it explicit that 2 is present and 3 is not. In other words, nowa by itself means 2-limit, and noca by itself means no-twos 3-limit. Then we use your method to add on the non-primes. 3.4 would be noca plus wa 4th. I'm not sure about 4.6, would it be nowaca plus wa 5th plus double wa 8ve? Or maybe nowaca plus wa 5th plus wa 11th?
With 2.9.21, the wa 7th is also a generator, and could replace wa 2nd. The zo 4th could be replaced by the zo 3rd, because 21/(2*9) = 7/6. Or even by the zo 2nd 28/27. There should be a canonical form, so that one subgroup doesn't get two names. Perhaps we could have a convention that the odd limit be as small as possible? And as a tie-breaker, e.g. for w2 vs w7, minimize the degree? Thus 2.9.21 would be nowa plus wa 2nd plus zo 3rd.
2.7.9 would be "za nowa plus wa 2nd". 2.3.7/5 would be "wa plus zogu". No need to say zogu 5th, since any zogu interval could be a generator, as could any ruyo interval. Or perhaps because 2.3.5 is ya not yawa, we can simply call this zogu? --TallKite (talk) 11:55, 22 July 2020 (UTC)