Thinly slice equal amounts of red, green, and yellow sweet peppers (throw in orange ones too, if you find them).
Layer the peppers into a jar as tightly as possible. Pick a jar with a wide opening for easy serving. I picked one that is more decorative to put on the table for some color while the peppers pickle.
Dissolve the sugar into the vinegar and bring to a boil. I think apple cider vinegar makes better peppers, but white vinegar works too (and looks better). Let mixture cool slightly.
Add liquid to jar, but leave at least one inch at the top for expansion before sealing. Store on counter for 24 hours out of direct sunlight. After that, store in the refrigerator for up to 10 days.
It is important to note that this is not canning. You can use the same recipe for canning, but add 1 tsp. of canning salt, use real canning jars, and process them per normal canning procedures. Enjoy!