Chuo Line Station Tiles?

Hi all, recently I've noticed that underneath the yellow lines on the train platforms of several Chuo Line stations, there seem to be cut off rows of old decorative tiles with images of plants and flowers on them. Since they're mostly cut off by the yellow line, only a little strip is left, but I've noticed small parts of gingko leaves at Mitaka station, and some sort of flower branch at Kichijoji station. Now I want to check other stations to see if I can find more, but I was wondering if anyone knows more about these? Any old photos or info? I've seen things like this before at some downtown metro stations as well but I can't remember which ones.

by Puzzled-Art-956