The volume of this bag clocks in at 15 litres. It only comes in one colour, black, but it does look quite neat.
From Amazon
Wenger Prospectus 600649 16 Inch Laptop Briefcase,15 Litre, Black, 33x15x42cm
BT Business Store
Wenger Prospectus 16" Business Case
This product is also available at 4 unverified stores.