Absolutely not the case. You may be remembering wrong, misunderstood, or were simply misinformed. Regardless, color will change the same in either container method (all dependant upon length of time).
The primary reason for using glass (for most) is usually: preventing flavor leeching (the majority), or the convenience of the glass dropper.
Can't help with the 500 gram scale limit... But as for the pouring aspect, there are miniature stainless steel funnels out there that are perfect for pouring large batches into 30ml bottles (available at Amazon, among other places)!
Good luck with whatever approach you decide to take though! =)