Most of the time, i don't like the look. I'm still trying to figure out if I like it on this pipe. When I first looked, it caught my eye. I know I don't want it if it is going to yellow or tarnish over time.
I recently bought a Peterson Christmas 2017 pipe which has a white acrylic stem. I've only had it about two months though, so I've only been through a dozen bowls or so. Thus far it hasn't changed color at all. I'm interested to see if it eventually does or not. Good question
The airway will darken overtime, and may show up a bit in the thinner material in front of the button. A lemon juice soak will clear it up, as alcohol tends to cause fine cracks in acrylic.