We have a lot of bluejays around right now as the young have fledged and are coming into our feeders.
Blue Jays are known for their intelligence and complex social systems with tight family bonds. Their fondness for acorns is credited with helping spread oak trees after the last glacial period.
The pigment in Blue Jay feathers is melanin, which is brown. The blue color is caused by scattering light through modified cells on the surface of the feather barbs.
source - Cornell Lab of Ornithology.