The closure mechanism on this running backpack is a zipper. Maybe not a good choice if you prefer lots of colour choices, but it does come in green and it holds two litres.
From Amazon
CAMELBAK Unisex's Classic Light Hydration Pack, Agave Green/Mineral Blue, One Size
Skinnergate
CAMELBAK CLASSIC LIGHT HYDRATION PACK 2021: AGAVE GREEN/MINERAL BLUE
Sigma Sports
CamelBak Classic Light 4L Hydration Pack + 2L Reservoir