A backpack such as this one can be very useful for a number of things. It only comes in one colour, red, but it does look quite neat and it has a 40-litre volume.
From OnBuy
Montane Fast Alpine 40L Backpack
Trekkinn
Montane Fast Alpine 40l Backpack Red M-L
Cotswold Outdoor
Fast Alpine 40 Rucksack
GearFreak.uk
Montane - Fast Alpine Backpack 40L Red