I know some Casinos track purple chips and higher. I know some casinos used to use chip technology to track bets (KC talks about this in his documentary) but I don't believe this is common anymore. In general, the way tables are going to monitor your win/loss is simply by seeing how much you buy in for and how much you color up for. If you bought in 3 times at a table for $500 each and then colored up for $700, they insert that data and assume you lost $800.
If you are playing rated this is attributed to your name/card, if not then it is more anonymous data. You could always squirrel chips away but I have been in smaller casinos where the PB comes over, counts the tray, counts the players stacks, and says "who has chips in their pocket". So just depends on the casino.