T. I made the salad and the flavor was very good, however, between the regular balsamic vinegar, the addition of sugar to the carmelizing, and coo...

Hmmm, I'm sorry to say that I don't have a sure-fire answer. First of all, my onions usually turn out browner than the Food52 test kitchen photos also, and I can assure you that it's still delicious, even though it's not as pretty! It also seems to vary a lot from onion to onion--I've found some keep their color more, and I'm not sure why (maybe based on age?). You might try a little less heat, or cooking them for slightly less time. If you try white balsamic, I'd love to hear how it turns out. Perhaps others who've tried this recipe have some better answers for you.