Whether for school or work, you can always find a good use for a backpack. It only comes in one colour, black, but it does look quite neat.
From Bikeparts
Camelbak Sparta 3.0L With Mil Spec Crux Lumbar Reservoir 2021: Black 33L
GearFreak.uk
CamelBak - Sparta Mil Spec Crux Lumbar Backpack (38L) Black