Now that you mention Silvertone, I wonder what the picture looks like on my NOS 1962-3 Silvertone 21FBP22?

I was blessed enough to find a good used Silvertone 21FBP22-RCA built it. I would guess that Sears would want a decent quality tube since they sold so many service plans.

Speaking of CRTs, what was with the GEs that had the blue face when off? I remember seeing ads for them but not many sales if I remember right. What was their point with it? What gave it that blue color?

mitsubishi had a "blue diamond crt" back in the late 80s,early 90s?i saw a few and they were very nice to watch.g e had a pretty sharp crt in the 70s.a little grainy but a nice look.most crts were pretty good except the low level rca sets from the late 60s and that horrible motorola 23 inch crt.some admiral 23v crts were dreadful too.the motorola was the worst of the lot in my opinion.i once spent days trying to make one look good in the shop.mr dixon then relieved me by saying,"you ve spent enough time on it.it will never look better than it does now.the crt is the worst ever made.i just wanted to see how long you would tinker before you gave up."then he explained business to me.labor costs,etc.i learned so much.but i still never give up!

Mostly a gimmick, done with blue glass (?) or a blue coating, don't know which. I also have ads for GE black and white tubes/sets that had an especially blue color (I think the phosphor rather than the glass), so they had a history of doing this.

I have a sales flyer for those GE sets, they called it Neovision. I think it was only used on their top of the line sets. I knew a couple people who had them but I never noticed anything special about the picture. Might have been made up until they bought RCA? The last one I saw was a few years back, owned by a friend of my wife. The crt was noticeably weak.

I think I've seen a few late GE and early Thomson era GE's with the "blue tube". Some of the Panasonic built GE branded consoles also had the "blue tube". Also, I had a 19" GE "PC" chassis stereo TV with the blue tube.

My opinion:
Telefunken A66-510X
Valvo/Philips A66-540X
18'' Trinitron 1977
Today I fixed an late-70's Indesit with a Sylvania delta, seems to look good but I have to make a correct convergence adjusting before judging it.

I think all their replacement CRT's were Sylvania rebuilts. They would milk the CRT for all it was worth before replacing it. I seen a lot of sets that were just off contract, that the CRT looked sick. That was true of both Sears and RCA.