The Davey Decimal System
Paint brands don't agree on much. The same warm white might be called "greige" by one company and "warm neutral" by another, with no shared way to say how warm, or in which direction. The Davey Decimal System fixes that — one number, three parts, that describes any color's undertone the same way no matter what brand it comes from.
How to read the number
A Davey code looks like this: 317.6
- First digit (3): the undertone family. There are 9 families, numbered 100 through 900, moving around the color wheel like hours on a clock.
- Next two digits (17): where the color sits within that family, from 00 to 99. Lower numbers lean toward the family before it; higher numbers lean toward the family after it.
- After the decimal (.6): how strong the undertone is, from .0 (barely there) to .9 (unmistakable).
So 317.6 reads as: solidly in the Yellow/Gold family, leaning slightly toward Orange/Terracotta, with a fairly strong presence.
The 9 families
| Code | Family |
|---|---|
| 100 | Red |
| 200 | Orange / Terracotta |
| 300 | Yellow / Gold |
| 400 | Yellow-Green / Olive |
| 500 | Green |
| 600 | Teal / Blue-Green |
| 700 | Blue |
| 800 | Violet / Purple |
| 900 | Red-Violet / Magenta |
| 000 | True Neutral — no detectable undertone |
Why it exists
Two colors don't have to be identical to land in the same Davey class — matching numbers mean matching undertone character, not a pixel-for-pixel match. If a color you love comes back 317.6, any other color classified 317.6 in any brand carries that same warm, yellow-gold character, even if the names and catalog numbers have nothing in common. That's the whole point: a way to talk about undertone that doesn't depend on which company mixed the paint.
How it's different from Delta E
You'll also see a "ΔE" number next to some colors on this site. That's Delta E — a real, decades-old color science formula for how different two specific colors look to the human eye. It answers "how close is this exact match." The Davey code answers a different question: "what kind of color is this, on its own." Delta E finds the closest match; the Davey code tells you why it's a match.
The 9 families, in real paint
Real catalog colors, not mockups — one per family.
Sherwin-Williams SW-6313 — near the center of the Red family, moderate undertone strength.
A Taubmans terracotta — sits mid-family, leaning toward Yellow/Gold.
A Taubmans gold — solidly in family, leaning toward Yellow-Green/Olive.
Dulux 1186945 — a classic olive, dead center of the family.
Benjamin Moore 592 — true green, leaning toward Yellow-Green/Olive.
Valspar M249 — a clean teal, leaning toward Green.
Behr P520-6 — solidly Blue, leaning toward Violet/Purple.
Valspar 4002-10B — center-family purple.
Clark+Kensington 02D-4 — leaning back toward Red, closing the wheel.
About this system
The Davey Decimal System is a DigiTool Shed original — not an industry standard, not affiliated with any paint brand or the actual Dewey Decimal library classification system. It's computed directly from each color's published RGB value using CIE Lab hue and chroma, the same math behind the undertone analysis elsewhere on this site.
Try it yourself on the Paint Color Matcher — search any color and open the Undertone section's ⓘ to see its wheel.