Ok. That's much better. The purple stuff that I saw is a reflection of your overhead lights or of some LED strips or something that is slowly color cycling. That's why anytime you're trying to show a video of the CRT neck, you need to record it with the lights in the room lights turned off.
Anyway....that looks and sounds normal.
The orange glow is from the filament heating up (just like an incandescent lightbulb). It's normal and correct.
The sound is "vector chatter", caused by the deflection system. It's also normal and correct.
Respectfully disagree. Something is wrong here. That sizzling sound is more than just chatter. He also had chatter before, as he's had XY deflection the whole time, the root cause from the beginning has been a Z issue. So if he's hearing a new sound, it isn't chatter.
Also, to my eye that neck glow is MUCH brighter than it should be. It's nowhere near that bright on my AD. It almost seems like a tube issue, however I suspect and hope that's not the case, and it's just something else that got messed up when he did the cap kit, since it wasn't sizzling before that.
@SpellboundLogic, remove C603 and 703. If they are backwards, that's going to cause problems. (And if they were installed backwards, they're going to be damaged, as you can't install electrolytic caps backwards.) Those caps aren't needed anyway, as they were removed on later versions of the board. So just remove them.
I think you have multiple issues going on here. I still think there's something wrong with your deflection board, which is affecting the Z signal. (Potentially the spot killer circuit, or the Z circuit itself.) Plus if those two caps are backwards, that's going to be a separate issue.
However from your video, your HV is also too low. You can tell that from the fact that the picture is very bloomed/zoomed in, which you could see for a second when you turned up the brightness.
You capped the HV cage. However the thing that actually causes more problems on these is the HV diode contacts being dirty. I have a long post about this
here. This is the most likely cause of your low HV.
Fixing that is something that all cages need. At a minimum this requires disassembling the diode/boots/springs, and cleaning the boots out with acetone and Qtips, to get all the dried grease out. Then you should solder the springs to the diode. This is tricky to do because the springs are steel, and requires good solder, a good iron, and everything to be clean bare metal. But it's the best way to fix it permanently and prevent the problem from coming back. There are some tips in my post above.
Note that your HV diode may also be bad, which can happen if these are run too long with dirty contacts. 95% of the time they are still ok, but you won't be able to know until you clean the contacts and test the cage again.
At this point, you may just want to send the deflection and HV in. I can refurb them both for you if you want.