Okay so we know that the Covey got rounded up and trapped in 12, correct? But what if it wasn't all of them, what if one or two made it to 4?
Eventually a couple generations later a girl was born, they debated over her name until deciding on Annie. Now there isn't a poem or ballad with Annie (not that I know of at least) but there is one close to it.
Annabel Lee, by Edgar Allen Poe.
Naming her Annie instead of Annabel makes more sense, knowing how much Snow (and everyone else) hates the Covey. And we know from Barb Azure that if the ballad has a double name then they just do the first one.
So they named her Annie, which explains how that's what everyone knew her as and what name she was reaped under, but its still close enough to be counted as (in my opinion) A Covey name.
Now why the ballad of Annabel Lee specifically?
"in a kingdom by the sea" we know D4 has to be near the sea or at least a body of water since its main purpose is fishing.
"The Angels, not half as happy in Heaven, went envying her and me," the Angels in Heaven are the Capitol cizitens, and we know that (most) everyone wanted to be, or thought they were, Finnick Odairs lover.
In the Annabel Lee poem, Poe is singing about his love that died. But with Annie's story, its the opposite.
Its Annie's love that dies, which still makes the poem come true in a way. But in stead of it being 'Lucy Gray was named from a child that vanished then she vanished' its 'Annie was named from a poem about a dead lover, then she lost her lover," which I think might be more tragic but that's just my opinion.
As for the color, I'm stumped, I've never been good at finding colors for Covey names.