Maybe we are lucky here in England then.
We get these 3 types.
EBJD = electric blue marble colour, sometimes black with marble blue
Sandy = these are the bog standard JD's, look alot liek Texas cichlids when young, except they have a lot of blue spangling on the fins (with the red edging) the body is a creamy brown colour.
Black = regular JD but a lot darker with brighter blues, usually the same price as the standard less desirable sandy coloured JD's (around £2.50) they are usually in seperate tanks from the sandy type, and have similaritys with a convict, but much darker, with the blue spanglinh and red edging.
There is a serious noticable difference between the sandy and black types, neither are from the EBJD breeding batches...wich look very different again.
I'm off to buy a few cichlids tomorrow, i will pick up a sandy JD as they are so cheap, and take photos of all 3 types of JD's (as i have the black and EBJD) and post them up so i can show you what i mean.
This is what i can grab from google.
Black regular JD
Sandy regular JD
EBJD