Cambridgeshire County Council said it wanted to upgrade all street lights in the county to LED bulbs over the next 18 months.

“Bright street lights also attract the flies and insects the bats feed ... green and red street lighting – the latter using ~630nm (‘high-efficiency red’ or orange-red) LEDs. The Nieuwkoop lights ...

The advantage to using a blue LED and a yellow phosphor is its high theoretical efficacy, which is attractive for the creation of a cheap, bright ... for outdoor lighting (street lights).