Quick trivia that saves me from my 3 a.m. eye twitch: the “blue side out” thing only applies to some surgical masks, and it’s meaningless on N95s (looking at you, 3M 1870+). Check for the nose clip/printing and the fluid-resistant layer — manufacturers flip colors all the time, which is why I keep hearing “you’re wearing it inside out” in the med room and it’s wrong half the time.
I’m with you — on the 1870+ I just make sure the “3M” printing faces out and the soft nose foam is toward me, which ends the 3 a.m. “blue side out” debate; if there’s no printing, I double-check the IFU for that model.
On tie-on procedure masks, I ignore color and look for the pleats to face down when it’s on; if the folds waterfall toward your chin, you’ve got the splash side out, which ends the 3 a.m. “blue side out” debate. Small caveat: a few brands flip the pleats, so I check for an “outside” stamp or the stiffer, fluid-resistant feel before I glove up, @OP.