"By night, the Eco Halos hover in suspended animation above the busy junctions. Colour changes occur imperceptibly in response to environmental conditions or as programmed by artists. [...]
"The Halos will be solar powered and use a mix of low energy red, blue and green LEDs within a polycarbonate diffuser to create a spectrum of soft glowing colours which will be clearly visible in the daytime. The combination of directional LEDs and a directional diffuser controls night sky light pollution and unwanted light spillage."