LynnaePB
Free Ranging
We saw some bobbing around. I've attach a photo of the masses I'm questioning.
I'm not seeing blood vessels but they can be hard to pick up in photos. If you see them they should be just fine.

There are lighter spots and darker (like the ones in your photo) as the egg develops. The darker spots are due to the yolk I believe (which is no issue as long as you are also seeing blood vessels).
That half light half darker appearance is very normal at this stage. As the chick grows and the blood vessels develop more and more it will change.