Boraras lost color?

I understand that the dominant male will take on the brightest color. Do you think his position in the new hierarchy in your tank caused him to lose color? Since I have these, I'm curious, as well. I have one that is deep red, but the rest while not quite as colorless as your second pic definitely aren't solid red all over.

I supplement crushed flake and crushed NLS with baby brine shrimp (fat).

first of all your fish is now healthy and fine. just look at it. fat and round. it is clear that the fish was starving at the purchasing time. second it is possible that this is a male ...and not a dominant one.
also boraras species like characins do look better (brighter colors) in blackwater conditions . do you have bogwood/driftwood/terminalia catappa leaves in the tank?

A piece of mopani wood yes, but soil buffers everything back to pH 7, even when I tan the water completely brown with IAL / humic acid. Ohwell, clear fish it is! At least it's healthy.

For such a tiny fish (0.75") I'm surprised they come up to the glass to beg you for food, instead of running and hiding.

These are my absolute favorite fish and imo they will all light up when they get comfortable. I originally had some left over from a year ago and they are all super red. A month ago i bought a few more and add half of those to my establish group and those guy turn red but not as bright as my original group. However, the other half i place in new tank look like yours but give them some time and they will all brighten up, even the female.

Xenxes,

This week I also began adding Omega One Color Plus to my Bbs diet, and they are showing more color in just a few days. You have to really work to crush up the flakes small enough. Other flakes tend to crumble into a finer powder just between my fingers, but Omega One requires some grinding. I found the Omega One at my local Petsmart.

My complete feeding regimen is now:
Crushed Tetra Flake
Crushed Tetra Tropical Crisps Color+
Ground NLS Small Fish Formula (still must be ground smaller)
Ground Omega One Color+ Flake
Ocean Nutrition Instant Baby Brine Shrimp

I am also going to add some frozen bloodworm to their diet. I think the more variety the better, and I've heard bloodworm can really color them up. I was not very smart, because I didn't order some of Rachel's fish food when I placed the order. I'd like to try that, too.