---
name: Seed color
slug: seed-color
category: color
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: The single input colour an algorithm expands into a whole scheme, so
  a palette becomes something derived from one decision rather than picked
  swatch by swatch.
aliases:
  - name: source color
    source: material
  - name: key color
    source: material
  - name: base color
    source: community
  - name: primary seed
    source: community
tags:
  - theming
  - tokens
relations:
  contrastWith:
    - hct
    - color-harmonization
    - brand-color
  variantOf: []
  partOf: []
  seeAlso:
    - material-you
    - identicon
implementations:
  - system: radix
    name: Custom palette generation
    url: https://www.radix-ui.com/colors/docs/overview/custom-palettes
sources:
  - title: "Material 3: how the color system works"
    url: https://m3.material.io/styles/color/system/how-the-system-works
demo: inline
exhibit: false
useWhen: one colour in, a whole palette out
---

A seed colour is an input, not a swatch you ship. You hand the generator one value and it
produces the rest: a ramp of lightness steps at that hue, a set of neutrals tinted towards
it, and the role assignments that say which step is a button fill and which is the tinted
background behind a notice. Nothing downstream names the seed. Components ask for the roles,
so changing the one input re-derives every surface at once instead of sending someone
through a stylesheet replacing hex codes.

The reason this works is that the generator does its arithmetic in a perceptual space.
Material's HCT holds hue and chroma from CIELAB and takes its tone axis from a contrast
model, so tone 40 against tone 100 lands on a known contrast whatever hue arrived, and other
tools do the same job in [OKLCH](/oklch). Because the lightness ladder is fixed and only the
hue is unpredictable, an arbitrary seed still produces an accessible scheme. That is the
whole trick, and it is why the rungs are usually numbered: "step 11 on step 2" is a rule that
survives a change of seed, while "this blue on that grey" is not.

Where the seed comes from is the interesting part. Usually it is the
[brand colour](/brand-color), carried in once and then left alone. It can also be extracted
from an image, which is what [Material You](/material-you) does when it reads source colours
out of a wallpaper and every app on the device shifts together. Some systems take more than
one: a secondary or tertiary seed for accents that should not simply be the primary hue
rotated, and a neutral seed that decides how warm the greys are.

Two cautions. A seed is a starting point, not a guarantee: generated ramps drift at the
extremes, near-neutral and very light seeds behave badly, and any serious system checks the
output and pins overrides rather than trusting the curve. And a generated scheme has no
opinion about meaning, so anything carrying a fixed sense of its own, a
[status colour](/status-color), a chart's categorical series, an illustration, needs its own
answer before the seed decides for it.