Definitely a shed issue. The dullness is normal. Both of mine look just like that while in blue. Usually lasts a couple days before they will clear up a bit. Then a couple days later they will shed.

I keep my juvenile BRB at 70 - 80% in the enclosure with a humid hide made from a small shoe box size Sterilite tub full of Sphagnum moss. Keep the moss damp, but not soaking wet, as well. Also make sure you have a water dish large enough for him to completely immerse himself in. I keep my six month old female in 85 -90% humidity.My male will take a soak just before a complete one piece shed.

As bad as his head looks I would secure him in a damp pillow case for a couple hours and let him squirm around. Keep misting the pillow case occasionally, but don't get it too wet.

What do you use for an enclosure? If it has a screen top you need to cover it with either a sheet of plexiglass, or aluminum foil to hold the humidity. Are you using a UTH or overhead dome light? Dome lights will kill any humidity very quickly.

You need to read a BRB Care Sheet ASAP to get a clear understanding of their needs. While more difficult than say a ball python, once you get everything right it isn't hard at all.