I read in recipes all the time- "try not to let the onions get any color", "being careful not to let the onions start to brown", "just cook the onions until soft and translucent", etc. Why not? I'm sure I always take my onions further than they are really supposed to go. I don't always caramelize them, but maybe just to the point that they are just starting to get some color. It is just an aesthetic thing? Like in a bechamel sauce, or whatever, where you wouldn't necessarily want bits of browned onion running through it. Or are there other reasons? What do you usually do?