Yes, the "Heartbeat" ones are black I think.
The white one is very Carnaby Street Austin Powers.
There's a Gardai one shown here, it's condition isn't as good as yours.
https://www.flickr.com/photos/35171459@N02/5643983339/
It's in a darned sight better condition than my old Noddy bike helmet though. This tatty lid had "PC 65" written in it.
Are there any markings in your Corker, a policeman's name or number?