My baby born on 26th sept and her weight is 1.44kgs, she is pre term baby born 30weeks +4days, she kept at NICU till 19th oct, now she is 2.6 kgs. we didn't give her bath. at the time of birth she is fair but over the period her skin colour turns black, is that her permenent skin colour? does this change occur because they kept under warmer and when she had jaundice they kept under blue light is this reason or something else