A 15" X 15" square = 225 square inches. So any sort of vest with a front & rear panel 15" X 15" would be 450 square inches.
Can't speak for other state's regulations but here in Illinois the orange is required to be
solid orange. So no camo-pattern camo or back patches or anything like that. That goes for hats also.
Here's the wording..........
Blaze Orange Clothing Requirements
It is unlawful to
hunt deer with any firearm when
not wearing a solid blaze orange cap/hat and an
upper outer garment displaying at least 400
square inches of solid blaze orangematerial.
NOTE:
Camouflage blaze orangematerial does notmeet
the requirements.
Another newer regulation here is when using a ground blind on public land you must displaya minimum of 400 square inches of blaze orangeon the outside of the blind visable from all directions.
Here's that wording..........
Blaze Orange Requirement – Ground Blinds on Public
Hunting Areas. It is unlawful to use or occupy a
ground blind during any firearm deer season on public
land unless at least 400 square inches of solid vivid
blaze orange material is securely attached to the uppermost
portion of the blind and a substantial amount
of orange is visible for 360 degrees.