I'm visiting rels for the holidays, and have a beater mid-90s Trek 820 here that I'm fixing up. Many components have been changed on it; the wheels are not original. They are Araya rims w/Shimano hubs that look 1990s-ish and I've attached a photo closeup of one. The question: what size spoke wrench (black, green, red) should I buy for truing purposes? I don't have a caliper handy. Your guesses/suggestions are appreciated!