Long before PAL Brittan and parts of europe were experimenting with color after NTSC came into existence. I could see a large tube and set OEM like philips making their own color CRTs on an experimental basis. Philips actually produced a roundy color for both Canada NTSC and european PAL markets, but I believe it used a 21FJP22....It would be interesting to know if they made their own CRT or bought American
I have two Philips TVs with a round color picture tube.
The Philips 21KX100A has a RCA 21FBP22.
The Philips EL-5793 has no numbers on the picture tube. This has a brown connection to the picture tube. According to Philips an AX53-14. I don't know if Philips made this picture tube itself, but someone might recognize this picture tube.
Also two photos of a new RCA 21FBP22, bought in the Netherlands.
The Philips EL5793
http://www.marcelstvmuseum.com/photoalbum85.html
The Philips 21KX100A
http://www.marcelstvmuseum.com/photoalbum30.html