It is!

Phosphors varied considerably too. Faster phosphors were generally avoided due to the need for low refresh rates and or interlaced display lines.

An older black and white television, for example, used slower phosphors in order to minimize the impact of interlaced images.

Similar phosphors in green and amber, to my eye a bit slower, pretty much eliminated flicker at 50hz / 60hz. These phosphors did not fatigue users much.

Newer, color displays came with faster phosphors!

Fonts look very different because the response curves are different as this great piece covers well.