We have discussed this from time to time.
Some people prefer to stick to one color, silver/silver or gold/gold.
Others don't mind mixing gold with silver. I mix them up, as I do with most of my jewelry.
There are several Juicy Couture charm bracelets, not all are the heavy starter bracelets. But the charms are larger & heavier, so the bracelet has to be able to handle the weight.
I don't mind mixing, there are a few charms that mix the gold and silver colors on the charms themselves. The bat and mouse in cheese charms come to mind. The mixing does bother some people, however. I would say it's up to your individual taste.
I've never mixing silver and gold until yesterday that I really wanted to wear my 2006 snowflake (silver charm w/gold clasp), so I had it on a silver chain... and I love it! it's fun to try something new ^.^
I don't think it's necsesarily a faux pas to mix the two-- there are a lot of charms that have both gold and silver, though there are definitely some that I don't think work as well (ex. silver polar bear on a gold bracelet). I started with a silver bracelet but just gave in and bought a gold b/c there were too many gold charms I wanted and was hesitant about mixing. Just my two cents!