The Osprey Stratos 34 & 36 are both offered in bright orange. I have the Osprey Talon 22 (orange) and I often wish it was a little bit bigger. But aside from that, it's a great orange daypack.

Osprey Stratos 34

[Linked Image from osprey.com]

Wind in my hair, Sun on my face, I gazed at the wide open spaces, And I was at home.