When tubes show a lot of purple glow, it's because the vacuum isn't perfect in the tube, and the atmosphere in the tube is ionizing. It's not a feature, it's probably a flaw in manufacture. Some power tubes may have a light purple glow from stray electrons hitting the glass, this is normal.  Some tubes, like voltage regulators may use an alternate gas in the tube such as neon or argon and will glow purple or pink...but with power tubes no glow usually means an excellent vacuum during manufacture.

As for the transformer hum - assuming the amp doesn't have any manufacturing flaws, it's probably some stray voltage on the ground. If this is in a media room (which I'm guessing it is since you mention movies), try disconnecting the Coax cable (assuming Cable TV) and see if it goes away. That's often the culprit. If it doesn't go away with the cable disconnected, try disconnecting different gear in your setup and see if the hum suddenly stops with a particular piece of equipment removed.

If my guess is right, and it's some voltage on the ground, you might need an isolation transformer or other filter. Or if it's the cable companies line, call them and tell them to get out and fix their poor ground.