Newborn looks pale.. anyone have this happen?

My baby is 3 weeks old. I mentioned to the doctor last week that she looks pale mostly when she’s asleep. And I just had a scare. She was in her mamaroo while I was doing the dishes. I went back to check her and she looked pale like usual but I picked up her arm and she has a very cold hand and dropped it like dead weight. Scared the shit out of me so I abruptly woke her up..her color immediately came back and she was fine. Anyone ever have this happen to their baby?? My pediatrician said she is ok and it can happen, but I’m still nervous.

Update:

Took her to a different pediatrician. Will be referring to cardiologist for a work up because she said it’s not normal but doesn’t know why it’s happening. All vitals looked good today. Still nervous. Any mamas experience this with your littles??