Confused:

The Kanji 色 (color) contains the "huge comma-design/tile" 巴 which Heisig calls "mosaic".
According to Kotoban (iPhone app) the Heisig number is 2096 but my version of RTK1 (2009 edition) stops at 2042.

Since it's a primitive, it doesn't have a number in the book but it appears before "color" which is number 1753.
So what does the number 2096 refer to? Do the primitives have numbers?

And why does Heisig list it as a primitive in the first place? It appears as a full Kanji with 戦 in "competition with three contestants", with 舟 in "cockatoo" and at different positions in many other composites.

Thanks!

RTK3 picks up where RTK1 leaves off, for a combined total of 3007.

[Katsuo]

巴 isn't that common as a separate kanji, so it doesn't appear as such until RTK3 (which has an extra 965 characters for "upper-level proficiency").

Hmm, so this is the only case where he breaks his rule of introducing a (rare) full Kanji as full Kanji + mentioning its additional meaning as a primitive? That makes two entries for the same Kanji, unlike the other cases of Kanji appearing mostly as primitves.

Are there any "fanmade" numbers or identifiers for primitives that are recognized among RTK users or how are they talked about?

Characters 2094-2105 are primitives in book 1. In fact, they're in a section called "New Kanji from Old Primitives."