The role of colour

It's well known that when one person dumps a rubbish bag where it shouldn't be other people feel less inhibited about doing the same. And when one person parks where they shouldn't others fairly quickly join them.

But until today I've never wondered whether the colour of a bike left against the railings means that someone with similar-coloured rubbish bags is more likely to sling them nearby. (Or vice versa, of course.)

Off to find some more colour-coordinated rule-breaking.