Depends on state laws - in GA here, it can be red, white, or amber for the rear turns, the fronts are 'supposed' to be amber, I've run clears for 2 years w/o a problem. They're too busy pulling over people here for window tint to care about the color of your flashers. Seriously - as long as it WORKS I think you'll be ok. maybe out in the boonies the cops don't have anything better to do but pull people for their blinker color.
But - if you're trying to stay legal (Hey, this is the ATL gimme a break), then yes you will need to change BOTH - the housing changed to a clear/white housing, then the bulb inside changed to AMBER bulbs. (all clear bulbs all the way around btw)
I'm a law breaker myself.. Clears w/ xenon white bulbs for over 2+ years..