I wouldn't say they are strange colours. The lfs near me has mollies this colour-half orange half black some with white bellies some without and some with red eyes!
Those fry are adorable! I don't have mollies but my friend does when his had babies they were all born coloured and spotted! Some were half gold/half black, some were gold with black spots and some were just plain black or plain gold! They were all still the same colours when they grew up so you might find they will stay that colour.
I wish guppies were born coloured instead of having to wait!