October 7, 2026
Brightness Test: Know Your Color Quality
How well do you know the metrics that measure color in lighting?
Welcome to the first-ever Inside Lighting Brightness Test.
Starting this month, we'll give lighting people a quick way to test what they know, sharpen what they may have forgotten, and pick up a few useful details along the way. Some months will focus on standards and technical topics; others will dig into broader lighting-industry knowledge. Consider this the inaugural edition. Scores from this one go on your permanent record.*
*They don't.
This month’s quiz is presented in partnership with the Illuminating Engineering Society and is based on ANSI/IES TM-30-24, IES Method for Evaluating Light Source Color Rendition.
TM-30 is a standardized method for characterizing how light sources render the colors of objects, using a set of numerical measures and graphics to describe color rendition in greater detail than a single-number approach can provide. It is intended as a practical tool for evaluating and comparing light sources for general illumination applications.
Want to go deeper? Two good places to start:
10 Questions on Color Quality
