Notes · 20 Aug 2026 · 3 min read

Why we fit 2700 K, and amber on paths

Same street, same lumens, two colour temperatures. What changes, and what does not.

Colour temperature is measured in kelvin. Old sodium streetlights were orange, around 2000 K. Many LED replacements went in at 4000 K or more: white with a lot of blue.

Same street, two colours

The two pictures on this page show Thornhope with the same fourteen shielded lamps at the same brightness, once at 4000 K and once at 2200 K. Shielding already removes the light going up. Colour decides how much of what does reach the air scatters, and blue light scatters more.

The village street lit at 4000 K — 4000 K, 1,600 lm per lamp, shielded

The same village street lit at 2200 K — 2200 K, the same lamps and brightness

What we fit

DarkSky International asks for 3000 K or lower outdoors. We fit 2700 K on buildings and yards, where people need to judge colours, and 2200 K amber on paths and bollards. Both are easy to buy and cost the same as the white versions.