Color Science
How colors are measured
CIELAB is an easy way of giving every color a precise location in space. Color names are fuzzy — your "rose" and mine might differ — but CIELAB fixes that by plotting each color as a single point in a 3D space built to match how the human eye actually sees. Three numbers pin a color down exactly. Think of it as a color's address.
L* — Lightness
How light or dark the color is, from black to white.
a* — Green → Red
How far the color leans toward green or red.
b* — Blue → Yellow
How far the color leans toward blue or yellow.
From those three numbers, color metrics can be derived
Once a color is just three numbers, comparing and describing it becomes simple arithmetic. Each idea in this guide is just a different question asked of those same coordinates:
- Depth — how light or dark it is
- Undertone — which direction it leans
- ΔE — how different two colors are
Depth: How light or dark
Depth describes how light or dark a shade appears.
Deep
Bold and saturated. Vampy, plum, oxblood, deep berry.
Medium
Pigmented but not heavy. The everyday range, where most lip products live.
Light
Soft and quiet on the lip. Pales, sheers, washes of color.
Depth comes straight from L*, the lightness scale that runs from 0 (black) to 100 (white). In cosmetics, a shade under 45 counts as deep, 45 to 60 as medium, and anything above 60 as light.
Undertone: How a color leans
Undertone describes which direction a color leans, independent of how light or dark it is. Colors within the same family can be cool, neutral, or warm.
Cool red
Leans toward blue or pink. Berries, fuchsias, blue‑based reds.
Neutral red
Balanced, neither blue‑ nor orange‑leaning. True reds and balanced rose.
Warm red
Leans toward orange or yellow. Bricks, corals, terracotta reds.
The hue angle on the a*–b* plane, the direction the color points, gives the undertone: below about 12° is cool, 12–28° neutral, above 28° warm. These are rules of thumb; individual color families can use finer bands.
Depth meets undertone
The same space sorts colors into families, too: reds, pinks, nudes and corals each sit in their own region.
Hover or tap a dot to read it.Tap a dot to read it.
Family:
L* →
Hue angle ° →
Interactive
Discover lipsticks by depth and undertone
The lipstick color chart lays the whole catalogue out in this same color space.
ΔE: The distance between two colors
If every color is a point in CIELAB space, then the difference between two colors is just the distance between their two points. That distance is ΔE (Delta E), one number for how different two colors look to the human eye. The smaller the number, the more similar the colors. It's the industry standard for color accuracy in cosmetics, printing, and design.
ΔE = √(ΔL*² + Δa*² + Δb*²)
Like measuring the distance between two pins on a map, in three dimensions: square the differences in L*, a*, and b*, add them up, and take the square root.
This tool uses a refined version, CIEDE2000, which re-weights lightness, saturation and hue to match how the eye actually judges them.
The ΔE scale, in plain English
How noticeable is the color difference at each level?
≤ 1ΔE
Imperceptible
The difference cannot be seen by the human eye, even side by side.
Exact match1–3ΔE
Just noticeable
Trained eyes can detect the difference. Most consumers cannot.
Excellent match3–6ΔE
Noticeable difference
Most people can see a difference. Still in the same color family.
Good match6–12ΔE
Clearly different
The difference is obvious at a glance. Related shade, different depth or tone.
Approximate match> 12ΔE
Different colors
These are distinct shades. Useful as a reference point, not a substitute.
Different shadeHow ΔE is used in this tool
Each lipstick in the database has been color-profiled in CIELAB color space using computer vision. When you select a color on the wheel, the ΔE distance from that color to every product in the database is computed and the closest matches are surfaced, ranked from most to least similar.
From product photo to measured color
How do we get a color out of a picture of a lipstick? See the steps behind the 16,000+ shades in the finder.
Sources
CIE (2018). CIE 015:2018 Colorimetry (4th ed.). Commission Internationale de l'Éclairage. ISBN 978-3-902842-13-8.
Luo, M. R., Cui, G., & Rigg, B. (2001). The development of the CIE 2000 colour-difference formula: CIEDE2000. Color Research & Application, 26(5), 340–350.
Xiao, K., Zhai, Q., Li, C., Zhu, Y., & Pointer, M. R. (2017). Color difference evaluation for human skin. Optics Express, 25(18), 21212–21222.