Originally Posted by HillRider

True, 680 is the correct stuff and it is indeed green. But just specifying "green" (or "red") Locktite isn't enough as there are several grades of both green and red intended for various applications. AFAIK, for only "Blue" (Grade 243) and "Purple" (Grade 222) does the color uniquely specify the grade.

Note to the OP: If you use Loctite 680, or it's equivalent from other makers, those cups will be installed almost permanently and it will take high heat to remove them. If you go that route, I'd buy a brand new headset with cartridge bearings so the cups never have to be removed again.