My baby Red Eared Slider has pink/ red spots on his shell?

[melissa]

My baby RES has developed red/pink faint spots on his undershell. He also has very faint yellow/light green spots on the scutes of his top shell. He is eating and swimming normally. I condition his shell once a week with tetrafauna's vitashell, clean his water every 4 days, he has a heat lamp and a UVB lamp, a basking area, plenty of swimming space, a cuttlebone, and vitamin supplement in his tank. The reptilian at the aquarium told me he is shedding however I don't see any skin/scutes coming off so I'm not sure this is the case. Any guidance would be greatly appreciated as I'm extremely worried this could become a life-threatening issue for my little guy. Thank you!