Sorry I didn’t reply earlier.
Faraday and Simplex had two colors available for their bells and horns: beige and red.
Red devices are most common, since red is the standard color for fire alarm NAs.
Beige was probably used for general alarm (e.g. mounted on a piece of equipment as a warning device, or class change) or for aesthetic.
I think beige went out of style in the 80s either because of NFPA rules or manufacturing costs. They were made before my time, so I’m not entirely sure…
They’re both in their original paint.