How long dies it take for a newborn guppy fry to fully grow?

When do they start getting colors? When is the earliest age you can tell the gender? If so how can you tell the gender when they are young? I have about 70 fry but some are 2 months and the others are from all differnt times. But how old must they be to tell the gender? How can I tell the gender o the two month old ones?

Young guppies take 3 to 4 months to grow up. The sexing question has been asked before on Yahoo and the Best Answer was 2 months. By that time the anal fin on the male will begin to become a gonopodium, a sexual intromittent organ to imoregnate females. The females bellies will start to get visiblly fat. The colors come with sexual maturity. You may see a smattering of color before, but their basic adult colors are visible but not necessary fully deep by 3 months. You may have to wait a month on the 2 month old ones. Diet and temperature also make them mature either slightly faster or slower.

Guppies take 3-4 months to grow if housed properly. If not housed properly, you're gonna see a 9 month old guppy still 2 cm long (like mine that I used to have when I was stupid in fish keeping). My second batch of guppies showed it first colors when it's about 1 or 2 months old, that looks like black blotches on its tail (It turned out to be king cobra guppies). You can tell the genders by looking at the body shape, females tend to be lots bigger and fatter while males look small and skinny (compared to the females). When it's 4 months old, you can see that the females have rounded anal fin while males' anal fin turns into a reproduction organ called gonopodium that looks like a needle (similar to penis in human being). When old enough you can see the females' gravid spot (In my case, 1.5 cm females already have their gravid spots visible)... Good luck in raising the guppies!