Without trying to be argumentative or tell someone they are wrong, there is a big advantage to getting the proper bottles.
Accidents can & do happen. That is why they are called accidents. Any reasonable steps to prevent accidents is prudent. Even though you may not need brown in the bottle to protect the ingredients, it does kind of warn people there is something different, unless it is in the shape and color of a familiar drink, like beer.
It is just cheap insurance to get bottles that look like chemical bottles. JMHO