No tomatillos in (Northern) New Mexico. Only red/green depending on time-on-the-bush. Also (in restaurants) sometimes the red is hottest, sometimes the green is hottest. You have to ask. But, usually the red is a thin-ish sauce (like thin tomato sauce) while the green is more like finely chopped pepper pieces. And it is not just the hot-ness, there is a "flavor" to each that is quite subtle and delicious. And healthy (not fattening; a true "veggie").
Most people come back to NM for a periodic "chile-fix"; chile is said to be somewhat addictive.