platy fry 3 weeks old,when should color coome?

[fishme]

my 7 platy fry,are big and strong,except for one it's eating and it's
active but it is small,might be a male,i don't know

but anyways ,when should color start coming in?

[Sasquatch]

From what I remember of those we had, it was around 1.5 months when the first colors started apprearing. It'll take longer for the full coloration to show up.

As for sexing, it's usually around 3 months.