Terachrome Color-Changing Luminaire Demo

Color-Changing Luminaire

This demonstrates a seven-primary broad spectrum light source controlled by Terachrome. As you click and drag in the color picker, the intensity of the individual primary colors is adjusted so that the full mixture matches the selected colors. The scene imagery shows rendering changes.

Notes on Color Gamut

The white outline in the color picker shows the gamut of the primary colors used here. This gamut is much larger than the best gamut possible on the web, so the colors shown here are far less saturated than those visible in person. However the illuminated scene does show color rendering differences that occur due to spectral responses far outside the web gamut. For example, select the deepest blue in the color picker. The eyes of the Beanie Baby and some of the color samples fluoresce in response to the short wavelength indigo primary.

How it Works

Using an actual seven-primary LED light source, a spectrometer determined color and intensity information for each primary. Terachrome software generated a set of seven lookup tables, one for each primary, specifying the optimal mixtures for sample points over the gamut. Seven digital images were captured, each with a different primary as the sole illumination. Client-side javascript converts color picker selections to chromaticity, interpolates among the samples in the lookup tables, computes intermediate colors for the light source “fan”, and combines the digital images using alpha-channel blending.