mermaids would have to be dark-skinned and chubby to survive in the ocean
water isnt a great means of protecting oneself from the sun theyd have to be very dark if they were shallow mermaids and they didnt want to be constantly sunburnt and they may be paler if they lived deeper in the water but theyd have to be buff and/or chubby as hell to resist the water pressure and cold of the deep sea
what im saying is pale-ass white skinny mermaids are just unrealistic