Hi
your antique moonstone necklace and bracelet set sounds absolutely beautiful. Moonstone is a good luck stone especially for lovers and was often given as a gift. Moonstone was at the height of its popularity in the late Victorian era (1885-1901).
You will be happy to know that the blue color moonstone in your jewelry has not changed. The bluer the color of the moonstone the finer and more desirable it is.
Blue colored moonstone is higher quality moonstone and is becoming increasingly more rare to find in today's market. You might also find the link about moonstone jewelry on this site interesting - https://www.antique-jewelry-investor.com/invest-in-moonstone.html