Ay, at 5 days old, normal pa rin na may slight bluish or purplish tint ang mga kuko ng newborns dahil sa circulation pa lang nila na unadjusting, lalo na kung malamig ang room o medyo mapuyat ang baby, pero if they're getting pinker na by the day, that's a good sign! Best check with your pedia during the first week visit para ma-confirm na lahat okay lang, kasi they'll look at the overall color ng baby din, hindi lang kuko.