The closure mechanism on this toiletry bag is a zipper. Maybe not a good choice if you prefer lots of colour choices, but it does come in brown and it has a four-litre volume.
From Amazon
FJÄLLRÄVEN 24214 Gear Bag Large Sports Unisex - Adult Terracotta Brown OneSize, Taglia Unica, Sporty, One Size
OnBuy
FJ?LLR?VEN 24214 Gear Bag Large Sports Unisex - Adult Terracotta Brown OneSize, Taglia Unica, Sporty, One Size