Using milk frozen from first week?

ljhgrey

LO was in the NICU for a week so I spent a lot of time pumping and have a largish frozen stash from that first week.
I'd like to start using that frozen milk as I continuing pumping to build a fresher freezer stash.
The milk is a lot more yellow than what I'm currently producing, I am guessing its contents are different than the milk I'm producing now.
Are there any reasons why I couldn't give him that milk occasionally to use up the older stuff first?
Tia!