Unless I missed an additional illustration or link from Air Vent that you supplied, the ones referenced on that page are just the standard sized 50 sq in slant back louvre vents.
The ones in the attached photo from OP, ar significantly wider than those. I have seen them, but rarely.
I am extremely familiar with Air Vent and the “Ask The Expert” seminars, and have even provided Paul Scelsi some alternative application methods for expanding the usage with only a slight modification to their existing Shingle VenII design, where it could be used as a parapet wall vent, as opposed to leak prone aluminum strip bents commonly used in the real world.
BTW, If any of you have never attended the FREE Air Vent seminars, go to their web site and get their nex seasons schedule. You will all find them educational and enlightening.
The different colored area of shingles you are noticing eminates from just under each of the 2 lead plumbing vent pipe soil stack flashings. That is a chenical electrolysis (sp) reaction to downward flowing rain water picking up or having a reaction with the lead boot flashings. The result is that the immediate downward area gets “cleaned” off from any “algae” or microbial growth in that area continuously and will stand out from the rest of the roof. That just goes to illustrate how intense the microbial discolorization is on the remainder of this and all roofs.
Next time you are driving down a treet with some steeply pitched older roofs, look directkly below the sheet metal chimney flashings on the shingles below and any other metallic object on the roof. The cleansing action occurs from any metallic object, although the products sold specifically for this purpose are generally composed of either zinc or copper.