When you're staring at a wall of paint chips, it's easy to get lost in the names. But on the back of almost every professional paint fan deck or chip, there is a small number that tells a much more important story than "Misty Sea" or "Greige Lace." That number is LRV, or Light Reflective Value.
What is LRV?
LRV is a scale from 0 to 100 that measures the percentage of light a color reflects. A perfect, absolute black would be 0 (absorbing all light), and a perfect, brilliant white would be 100 (reflecting all light). In the real world of paint, most "black" paints sit around 3–5, and the brightest "white" paints usually top out around 90–92.
Why does this matter? Because color is an illusion created by light. If you put a paint with an LRV of 20 in a room with small windows, that room will feel inherently dark and moody, regardless of how many lamps you turn on. If you put a paint with an LRV of 80 in that same room, it will bounce whatever light it gets back into the space, making it feel significantly brighter.
The 50% Rule
A general rule of thumb used by many designers is that an LRV of 50 is the midpoint. Anything above 50 will start to brighten a room; anything below 50 will start to absorb light and darken the space. When you're trying to find that "perfect" neutral that doesn't feel too heavy but still has some body, looking for an LRV between 55 and 65 is often the "sweet spot."
Understanding this number changed how I choose paint. It takes the guesswork out of how a color will behave. Before you buy that gallon, check the back of the chip. It might just save you a second coat of a different color later.