Questions on brightness of old colour TVs

[Aussie Bloke]

Hi all. I've in the past read about the early colour sets including RCA CT-100 giving rather dim pictures and people have to watch programs with the light switched off to give a bright picture.

Just wondering between say 1954 and 1965 which colour tellies gave bright pictures and which gave dim pictures. I heard that the CT-100s gave low current emissions to the tube, was this corrected when the 21-CT-55 was released?

I also looked at the propaganda of the 60s colour TV ads advertising colour tellies saying they give much brighter picture than any of the previous ones. What is the truth in this?