I was reading somewhere that they are very similar to the Fire gene. Even so in the fact that the 'super' form is a Black Eyed Lucy.

I'm also thinking, don't hold me to it, but it shares a 'complex' (hoping that's the right term) with the Fire much like a Lesser and a Mojave. You could breed a Fire to a Sulfur and get a BEL as well.

I don't have any, so I'm no help with the pictures.