Thread:BunsenH/@comment-25404524-20170107010430/@comment-24577221-20170107025339

There's always light coming from a Glowbe -- mathematically, it's necessary that the sum of the red, yellow, and blue values equals 1. Every original Glowbe starts with 1.0 of one of the colours. If you combine two of them, the "child" is the average of its "parents", and therefore also has a total of 1.0.

A more-or-less white Glowbe has a very dark, more-or-less black body.