[lambretta]

do these all start off as blue juveniles and the females go brownish

brought some fish labelled as these and they are all blue but no colour in the fins yet

 

[DJRansome]

Here is the species profile and you can see pics of juveniles and females.
https://www.cichlid-forum.com/profiles/ ... php?id=794

 

[lambretta]

looks like i have some mislabeled fish then

i thought they looked more like Pseudotropheus socolofi Powder blue
one of them has a slight bit of back on the dorsal fin

 

[DJRansome]

I don't think black on the dorsal should be there at any age.

From your description (all blue juveniles) I was wondering about hormones.

 

[lambretta]

they are all pale blue with darker bars just about visable

 

[lambretta]

showed pictures to a local fish breeder /trader and she says they are cobalt blues

 

[DJRansome]

Still should not be any black on the dorsal of a cobalt blue (which is really Metriaclima callainos).