Indeed the only question in this, is if a +1 arrow is actually a magical attack or not...
I keep my opinion regarding the red veil: a +1 arrow is a magical missile (in the sense of "ammunition"), and, therefore, not subject to be blocked by it.
Now, the orange veil would be the likely candidate to block a +1 arrow, but only if the attack is considered magical. Personally, i rate the arrow as a "simple" magic weapon, not a magical attack, and that's also the general opinion in my gaming group.
I never considered the attack of a +1 longsword a magical attack. The weapon is magically enhanced, but it's still a weapon dealing weapon damage + the magical enhancement...
Bottom line, IMHO, the orange veil wouldn't cover it either, but i'm interested in seeing where the discussion on the +1 arrow goes.