Are you sure that the liquid lemi-shine is the same stuff as the crystals? I have in front of me a container of the crystals, which works good, and one of liquid "lemi-shine Rinse/performance booster. It doesn't work worth sh!t for shining up the brass.
Another possibility... have you used graphite to lube the inside of your case necks? A wee little bit will make your brass look darker, and takes a while to get cleaned out of the pins/inside of the drum. Ask me how I know this.
Other than aesthetics does it matter if the brass is brown? I have had my last two batches come out like this.



























