It made me think about the chairs at my primary school. They were grey plastic and came in various sizes - each size was denoted by coloured bolt type things that held the back of the chair on.
So the smallest chairs - the little tiny iddy biddy ones - had red bolts on the back and the slightly bigger ones had blue on the bag. But there was only one chair in our classroom that was the next size up from that which had green bolts on the back.
And there would be a mad schuffle for the green chair because then you would be sat ever so slightly higher than everyone else (except for the teacher).
I wonder whatever became of the chair... you never know, maybe it's still at my old school somewhere.