Guppy Fry Color Question

[Aequora]

My green female guppy squatted out a small handful of fry for me about.. oh, say, two-three weeks ago? Off the top of my head, I think there are six of them, or nine. They're all still alive. I let the fry live in my largest breeding box until they finally got their bearings and then I moved them to their own rearing tank. They are growing very well and were just about the smallest fry I have ever seen-probably less than a 2cm long x 1cm deep. Within this last week, some have developed dark spotting on the base of their tails, so here's my question. Around what age does the average guppy start developing its adult colors? I could post pictures if I could get any of fish that small. They've probably grown one cm long since birth, but they are half the size of the molly fry I have in with them that were born around the same time. =]

 

[Duck and Dive]

Give them another month and they will start getting their colours.

 

[OldMan47]

I sometimes see minor spots on very young fish but to get a good idea of final colors they would be at least 6 to 8 weeks old. At 4 months they will have a nice coloring showing up but true adult colors often continue to develop and deepen past 6 months of age. Mollies are much larger fish at birth and continue to be larger than the guppies for at least 2 months. By then, the faster growth rate of guppies often catches up temporarily but the much larger final size of mollies means that they soon pull ahead on size again.