“Seeing the True Colors of LEDs” –  some good geeky information about how our brain, eyes, and LEDs (light-emitting diodes) interact with each other.

Let’s start with a bit of biology. Apparently, the human brain has a really easy time compensating for changes in color intensity but they’re not so good at discerning differences in light intensity.

Now about bit about color rendering. The color rendering scale, or CRI, is measured on a scale of 100, with 100 meaning colors appear as true as possible. A score of 80 or higher is usually sufficient for viewing objects with the naked eye in true color. Anything lower and we’ll be seeing something that’s a bit off.

Most incandescent light bulbs throw light that scores an 80 on the CRI scale, and some fluorescent bulbs (the long office-type tubes) often have a CRI of 60-65, which is why they often appear yellow. If you’ve ever shopped in a clothing store lit by fluorescents, you know the frustration of bringing a shirt home that looked perfect in the store but actually doesn’t match that favorite pair of pants in real life. Sigh.

LEDs, on the other hand, combine yellow and blue wavelengths that mix to provide a light that appears white. These lights work well for outdoors, but aren’t ideal for indoor lighting.

There are, however, alternatives that provide truer color rendering. These are called RGB (red, green, and blue or red mixed) or RGBA (red, green, blue, and amber mixed) LEDs. This technology has been available for many years, but because red and amber chips in LED lights are somewhat unstable, they haven’t been all that popular. But they’re beginning to see improvements and drops in prices. The moral of the story? You’ll want to choose your LED bulbs to suit the purpose of the lights. Do a bit of research before plunking down your cash.