This should be a pretty easy question to answer by simply looking at the tons of old literature and period photos. White tires had zinc-oxide in them as an additive to improve wearing characteristics, later tires had lamp-black carbon in them for the same reason.
If you look at the Pierce serial-number thread it shows a Pierce display at a large show in 1914 and all it's bikes still had white tires, and they had white tires in earlier advertising material shown in that thread too. After WWI black tires seemed to show up more often. One article said that during WWII white-wall tire production was stopped, maybe the zinc-oxide was a strategic material.
Also red-tires were common early on because iron-oxide was used, and we have seen early blue tires too, but I do not know what made them blue.
In early black and white photography, red or blue tires may show up as being white or black or grey depending on the film.
If I had a common brand-name bike I would simply look up some old literature for it, if I could not find any I would just go with what the literature of other similar brands showed.
So the first question is how old is that Century Marathon bike? And then is there any period literature for it?
