Hello I am a new bee keeper and got my first Nuc on April 10. I put them in the brood box and they have been doing fantastic. Queen is laying and I have some capped brood and honey.
Question is when should I put the flow super on top?
Also some of the cells are a bit orange you can see in the pic. Is that just the pollen?
!
They do seem to be doing very well.
General rule of thumb for putting a second supper (flow or normal on) is that the preexisting one(s) are approximately 90% drawn and 90% full of stuff (Brood of all stages, pollen, nectar and/or honey) and there is a flow happening.
Look forward to learning how you go.
Adam
Hi there Jeremiah and welcome! Yep, the orange stuff in the cells is pollen. Those are lovely new combs and a great start! Just a tip - be very, very careful when you are lifting and turning them, they’re very fragile and the more nectar in them the heavier they get.
Looking at your frames I agree with Adam and I don’t think your colony is quite close to being ready for a super. You want to see those corners and sides all built out to the frames, and I would say 80% full of nectar, pollen and brood, and covered on both sides with bees. Once things get that full, a colony will start planning to swarm, so it’s up to us as beeks to monitor and decide how and when to intervene. Maybe to settle the discrepancy of what percentage is the right one we should ask the bees 
Keep us posted on how it’s going!
