# American Express gradient

Gradients derived from American Express'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/americanexpress-com
- Brand colors: https://brandsweets.com/colors/brands/americanexpress-com · Brand page: https://brandsweets.com/b/americanexpress-com
- Palette: primary #2e77bc, secondary #005dae, accents #006fcf
- Source: https://americanexpress.com (extracted 2026-09-02)

## Brand gradient

ΔE_OK 0.081 < 0.15 between #2e77bc and #005dae — a 2-stop would read as a flat fill, so this is a tonal ramp of #2e77bc.

- CSS: `linear-gradient(135deg in oklch shorter hue, #67aff8 0%, #2e77bc 50%, #004282 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#67aff8] via-[#2e77bc] to-[#004282]`
- Contrast (worst point): white 2.32:1 fail · black 2.10:1 fail · banding high
- Maker: https://brandsweets.com/gradients/new/v1.67aff8-2e77bc-004282?a=135&in=oklch&hue=shorter

## Hero background

Chroma ×0.35 so it can carry text; ink white (inkFor at the midpoint). L shifted −0.18 until the ink passes AA at the worst point (4.64:1).

- CSS: `linear-gradient(135deg in oklch shorter hue, #5f7790 0%, #2a4058 50%, #0b1726 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#5f7790] via-[#2a4058] to-[#0b1726]`
- Contrast (worst point): white 4.64:1 AA · black 1.17:1 fail · banding high · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.5f7790-2a4058-0b1726?a=135&in=oklch&hue=shorter

## 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. L shifted −0.07 so white ink passes AA on the surface and both states (worst 4.69:1).

- CSS: `linear-gradient(180deg in oklch shorter hue, #246eb2 0%, #005698 100%)`
- Tailwind: `bg-linear-to-b/oklch from-[#246eb2] to-[#005698]`
- Contrast (worst point): white 5.32:1 AA · black 2.79:1 fail · banding high · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.246eb2-005698?a=180&in=oklch&hue=shorter
- Hover: `linear-gradient(180deg in oklch shorter hue, #2e77bc 0%, #0f5fa2 100%)`
- Active: `linear-gradient(180deg in oklch shorter hue, #1865a9 0%, #004d8f 100%)`

## Tonal ramp

- CSS: `linear-gradient(135deg in oklch shorter hue, #67aff8 0%, #2e77bc 50%, #004282 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#67aff8] via-[#2e77bc] to-[#004282]`
- Contrast (worst point): white 2.32:1 fail · black 2.10:1 fail · banding high
- Maker: https://brandsweets.com/gradients/new/v1.67aff8-2e77bc-004282?a=135&in=oklch&hue=shorter

## Analogous

Partner hue from the analogous rule at the source colour's lightness.

- CSS: `linear-gradient(135deg in oklab, #2e77bc 0%, #317f95 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#2e77bc] to-[#317f95]`
- Contrast (worst point): white 4.55:1 AA · black 4.46:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.2e77bc-317f95?a=135

## Complementary

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, #2e77bc 0%, #98692b 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#2e77bc] to-[#98692b]`
- Contrast (worst point): white 4.29:1 AA-large · black 4.39:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.2e77bc-98692b?a=135&in=oklch&hue=shorter

## Triadic

Partner hue from the triadic rule at the source colour's lightness.

- CSS: `linear-gradient(135deg in oklab, #2e77bc 0%, #c6355b 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#2e77bc] to-[#c6355b]`
- Contrast (worst point): white 4.66:1 AA · black 4.05:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.2e77bc-c6355b?a=135

## CSS custom properties (brand.css)

```css
:root {
  /* Brand gradient (derived) */
  /* worst-case contrast: white 2.32:1, black 2.10:1 */
  --brand-gradient: linear-gradient(135deg in oklch shorter hue, #67aff8 0%, #2e77bc 50%, #004282 100%);
  /* hero — worst-case contrast: white 4.64:1 AA, black 1.17:1; ink passes AA at the worst point */
  --brand-gradient-hero: linear-gradient(135deg in oklch shorter hue, #5f7790 0%, #2a4058 50%, #0b1726 100%);
  --brand-gradient-hero-ink: #ffffff;
  /* button — worst-case contrast: white 5.32:1 AA, black 2.79:1 */
  --brand-gradient-button: linear-gradient(180deg in oklch shorter hue, #246eb2 0%, #005698 100%);
  --brand-gradient-button-hover: linear-gradient(180deg in oklch shorter hue, #2e77bc 0%, #0f5fa2 100%);
  --brand-gradient-button-active: linear-gradient(180deg in oklch shorter hue, #1865a9 0%, #004d8f 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.