Slight Blue Tint with Color Down

[Outland]

I picked up a lightly used Panasonic set (CT-20S10S) with the same chassis as mine (CT-20S2S) as a potential replacement CRT. They are the same TVs, except the new one has composite input. They have the same remote and menus.

My old CRT is a little tired, with slight burn-in from closed captions and a slightly dim top right corner. With color all the way down, the image is black and white, maybe a very very slight green tint (maybe).

On this new one, there are no dim corners, no burn-in, and the image is significantly brighter and a little sharper.

However, with color all the way down, the new one has a slight blue tint. What is the reason for this? I can't imagine it's more worn than the old one, which doesn't have a tint with color down. Is this how the set was when new?