Just how much color CAN a Buttikoferi develop?
 

For some time, Marty (4" buttikoferi) has shown an almost neon blue in
the adipose area and along the very edge of the ventral vin when he is
excited. (My mantra, a blue fishy is a HAPPY fishy! :) )

Recently the color has expanded. The blue on the ventral fin now
extends about 20% of the width of the fin, along the entire back edge of
the caudal fin in the same thickness, and most excitingly, along the top
of the dorsal fin.

I don't have any full flare pictures at the moment, but the dorsal fin
when flared allows each segment to exist individually in the top 1/4 of
the fin. Seeing the bright blue (almost the shade of an electric blue
hap) on the tips of the individual segments is a sight to behold.

I'll try to get pictures the next time he colors up.