# Slack gradient

Gradients derived from Slack'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/slack-com
- Brand colors: https://brandsweets.com/colors/brands/slack-com · Brand page: https://brandsweets.com/b/slack-com
- Palette: primary #1264a3, secondary #730394, accents #1264a3
- Source: https://slack.com (extracted 2026-09-02)

## Brand gradient

- CSS: `linear-gradient(135deg in oklab, #1264a3 0%, #730394 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#1264a3] to-[#730394]`
- Contrast (worst point): white 6.20:1 AA · black 2.17:1 fail · banding high
- Maker: https://brandsweets.com/gradients/new/v1.1264a3-730394?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 (6.22:1) without adjusting L.

- CSS: `linear-gradient(135deg in oklab, #4d6379 0%, #5b4066 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#4d6379] to-[#5b4066]`
- Contrast (worst point): white 6.22:1 AA · black 2.37:1 fail · banding high · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.4d6379-5b4066?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 4.61:1).

- CSS: `linear-gradient(180deg in oklch shorter hue, #2370b0 0%, #005896 100%)`
- Tailwind: `bg-linear-to-b/oklch from-[#2370b0] to-[#005896]`
- Contrast (worst point): white 5.23:1 AA · black 2.84:1 fail · banding high · ink #ffffff
- Maker: https://brandsweets.com/gradients/new/v1.2370b0-005896?a=180&in=oklch&hue=shorter
- Hover: `linear-gradient(180deg in oklch shorter hue, #2d79ba 0%, #0d61a0 100%)`
- Active: `linear-gradient(180deg in oklch shorter hue, #1767a6 0%, #004f8d 100%)`

## Tonal ramp

- CSS: `linear-gradient(135deg in oklch shorter hue, #519bde 0%, #1264a3 50%, #003168 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#519bde] via-[#1264a3] to-[#003168]`
- Contrast (worst point): white 2.96:1 fail · black 1.64:1 fail · banding high
- Maker: https://brandsweets.com/gradients/new/v1.519bde-1264a3-003168?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, #1264a3 0%, #136c80 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#1264a3] to-[#136c80]`
- Contrast (worst point): white 6.01:1 AA · black 3.36:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.1264a3-136c80?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, #1264a3 0%, #865410 100%)`
- Tailwind: `bg-linear-to-br/oklch from-[#1264a3] to-[#865410]`
- Contrast (worst point): white 6.20:1 AA · black 3.15:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.1264a3-865410?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, #1264a3 0%, #af164c 100%)`
- Tailwind: `bg-linear-to-br/oklab from-[#1264a3] to-[#af164c]`
- Contrast (worst point): white 6.19:1 AA · black 3.04:1 AA-large · banding high
- Maker: https://brandsweets.com/gradients/new/v1.1264a3-af164c?a=135

## CSS custom properties (brand.css)

```css
:root {
  /* Brand gradient (derived) */
  /* worst-case contrast: white 6.20:1 AA, black 2.17:1 */
  --brand-gradient: linear-gradient(135deg in oklab, #1264a3 0%, #730394 100%);
  /* hero — worst-case contrast: white 6.22:1 AA, black 2.37:1; ink passes AA at the worst point */
  --brand-gradient-hero: linear-gradient(135deg in oklab, #4d6379 0%, #5b4066 100%);
  --brand-gradient-hero-ink: #ffffff;
  /* button — worst-case contrast: white 5.23:1 AA, black 2.84:1 */
  --brand-gradient-button: linear-gradient(180deg in oklch shorter hue, #2370b0 0%, #005896 100%);
  --brand-gradient-button-hover: linear-gradient(180deg in oklch shorter hue, #2d79ba 0%, #0d61a0 100%);
  --brand-gradient-button-active: linear-gradient(180deg in oklch shorter hue, #1767a6 0%, #004f8d 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.