Can different batches of jars of tomato sauce for pasta be different colors even if it is the same brand and flavor?
Did the lid "pop" or not? Tomato sauce darkens on exposure to air - has your jar been opened? Normally food-manufacturers insist on high levels of conformity between batches of the same product so this doesn't sound right
Tomato sauce darkens the longer it's cooked. Light/orange has olive oil or butter in it and it's not cooked down.
Yes. The tomatoes would not all have come from the same place, for example, and might be of different varieties.