Just think back to the last time you were driving any distance... ever look in your mirror and not see a car, only to be overtaken by one a few minutes later? It's usually one of the paler colours in daytime, and a dark car at night. Lighter cars show up better at night, but dark ones vanish. A nice mid range colour that is visible in the daylight but light enough to be seen at night turns out to be either yellow (there's a particular company that churned out metalic mustard yellow one year.... euugghh!), or a light to mid blue. Grey is visible at night but vanishes into daylight, as does silver.

Mind you if it was parked, maybe you should be looking at your parking space......

LTS