Color Temp is a free web app that makes Kelvin ratings make sense — soft white, daylight, warm white and everything between — with a visual spectrum, a Kelvin lookup, and room-by-room bulb recommendations.
Color Temp is the complete reference for light color temperature. Understand Kelvin ratings — soft white vs daylight, CRI, and what bulb to buy for every room — with visual light samples, zone explanations, and room-by-room recommendations.
It runs entirely in your browser. There is nothing to download and no account to create: open it, drag through the spectrum, and see exactly what each temperature looks like. For the full story on what 2700K, 4000K, and 5000K actually mean, the Kelvin explainer goes deeper.