Should I be concerned about this color baby poop?

Mariah

My son will be 3 months on the 10th and the past month or so he has stopped pooping every day. it's now every few days. so today he went poop after probably 3 or 4 days. and had a little trouble so I opened his diaper to give him space and the color was fine at first and then it started getting lighter, and the last little bit that came out was this color, should I be concerned?