# Signal gradient

Gradients derived from Signal's published colour tokens (nominative use; no brand assets). Deterministic: the same values are served as `--brand-gradient*` in the brand's brand.css.

- Page: https://brandsweets.com/gradients/brands/signal-org
- Brand colors: https://brandsweets.com/colors/brands/signal-org · Brand page: https://brandsweets.com/b/signal-org
- Palette: primary #1b1b1b, secondary #2942ff, accents #4258ff
- Source: https://signal.org (extracted 2026-09-05)

## Brand gradient

- CSS: `linear-gradient(135deg in oklab, #1b1b1b 0%, #2942ff 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#1b1b1b] to-[#2942ff]`
- Contrast (worst point): white 6.33:1 AA · black 1.22:1 fail · banding medium
- Maker: https://brandsweets.com/gradients/new/v1.1b1b1b-2942ff?a=135

## Hero background

Chroma ×0.35 so it can carry text; ink white (inkFor at the midpoint). Passes AA for that ink at the worst point (5.78:1) without adjusting L.

- CSS: `linear-gradient(135deg in oklab, #1b1b1b 0%, #4e649d 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#1b1b1b] to-[#4e649d]`
- Contrast (worst point): white 5.78:1 AA · black 1.22:1 fail · banding medium · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.1b1b1b-4e649d?a=135

## Button / CTA

ΔL 0.08 top→bottom in the primary's hue (a lit surface, not a rainbow); hover L +0.03, active L −0.03. White ink passes AA on the surface and both states (worst 13.96:1).

- CSS: `linear-gradient(180deg in oklch shorter hue, #242424 0%, #121212 100%)`
- Tailwind: `bg-linear-to-b/oklch from-[#242424] to-[#121212]`
- Contrast (worst point): white 15.52:1 AA · black 1.12:1 fail · banding high · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.242424-121212?a=180&in=oklch&hue=shorter
- Hover: `linear-gradient(180deg in oklch shorter hue, #2c2c2c 0%, #191919 100%)`
- Active: `linear-gradient(180deg in oklch shorter hue, #1d1d1d 0%, #0c0c0c 100%)`

## Tonal ramp

- CSS: `linear-gradient(135deg in oklch shorter hue, #484848 0%, #1b1b1b 50%, #000000 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#484848] via-[#1b1b1b] to-[#000000]`
- Contrast (worst point): white 9.15:1 AA · black 1.00:1 fail · banding medium
- Maker: https://brandsweets.com/gradients/new/v1.484848-1b1b1b-000000?a=135&in=oklch&hue=shorter

## Analogous

Primary #1b1b1b is achromatic — harmony rotates #2942ff instead. Partner hue from the analogous rule at the source colour's lightness.

- CSS: `linear-gradient(135deg in oklab, #2942ff 0%, #006e9f 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#2942ff] to-[#006e9f]`
- Contrast (worst point): white 5.61:1 AA · black 3.31:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.2942ff-006e9f?a=135

## Complementary

Primary #1b1b1b is achromatic — harmony rotates #2942ff instead. Partner hue from the complementary rule at the source colour's lightness. ΔH 180° > 140° — interpolating in oklch (shorter hue) keeps the midpoint saturated.

- CSS: `linear-gradient(135deg in oklch shorter hue, #2942ff 0%, #806200 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#2942ff] to-[#806200]`
- Contrast (worst point): white 5.11:1 AA · black 3.32:1 AA-large · banding medium
- Maker: https://brandsweets.com/gradients/new/v1.2942ff-806200?a=135&in=oklch&hue=shorter

## Triadic

Primary #1b1b1b is achromatic — harmony rotates #2942ff instead. Partner hue from the triadic rule at the source colour's lightness.

- CSS: `linear-gradient(135deg in oklab, #2942ff 0%, #c20011 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#2942ff] to-[#c20011]`
- Contrast (worst point): white 6.02:1 AA · black 3.29:1 AA-large · banding medium
- Maker: https://brandsweets.com/gradients/new/v1.2942ff-c20011?a=135

## CSS custom properties (brand.css)

```css
:root {
  /* Brand gradient (derived) */
  /* worst-case contrast: white 6.33:1 AA, black 1.22:1 */
  --brand-gradient: linear-gradient(135deg in oklab, #1b1b1b 0%, #2942ff 100%);
  /* hero — worst-case contrast: white 5.78:1 AA, black 1.22:1; ink passes AA at the worst point */
  --brand-gradient-hero: linear-gradient(135deg in oklab, #1b1b1b 0%, #4e649d 100%);
  --brand-gradient-hero-ink: #ffffff;
  /* button — worst-case contrast: white 15.52:1 AA, black 1.12:1 */
  --brand-gradient-button: linear-gradient(180deg in oklch shorter hue, #242424 0%, #121212 100%);
  --brand-gradient-button-hover: linear-gradient(180deg in oklch shorter hue, #2c2c2c 0%, #191919 100%);
  --brand-gradient-button-active: linear-gradient(180deg in oklch shorter hue, #1d1d1d 0%, #0c0c0c 100%);
  --brand-gradient-button-ink: #ffffff;
}
```

## Gradient maker

Every maker URL is the gradient's state: `/gradients/new/v1.<hex>-<hex>[_pos]?a=135&in=oklch&hue=shorter&e=soft&g=8`. Hand one to a human, let them refine, and read the link they return.

## Connect an agent

Point any MCP client at the BrandSweets gradients endpoint for the same engine and corpus:

- Endpoint: https://mcp.brandsweets.com/gradients/mcp
- Tools: `make_gradient` (2–5 colours → CSS with the interpolation space, Tailwind v4, SVG, PNG URL, DTCG token + the contrast/banding/gamut report), `brand_gradients` (brand slug or palette → brand gradient, hero, button, variants).
- Resource: `gradients://corpus` — the whole bundled corpus as JSON.