Brand gradient

Substack gradient

The gradient Substack's published colour tokens imply, derived by a pure function of the palette: primary → secondary in OKLab (OKLCH shorter hue when the hues are more than 140° apart; a tonal ramp when they are within ΔE 0.15), then a hero background with an ink that passes AA at the worst point along the line, a button surface with hover and active states, and the variant contact sheet. Same inputs, same gradients, forever — which is what makes them citable; the same values are served as --brand-gradient in the brand's brand.css.

#fc5404 #0083d5 #ff6719

Open in the maker Substack colors →Full brand page →

Source: substack.com
Extracted: 2 September 2026
Version: 5

Substack

black text · worst 5.18:1 · AA

white 3.28 AA largeblack 5.18 AAbanding medium

Hero and button

Hero background

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Chroma ×0.35 so it can carry text; ink white (inkFor at the midpoint). L shifted −0.10 until the ink passes AA at the worst point (4.60:1).

white 4.60 AAblack 3.40 AA largebanding high

css

linear-gradient(135deg in oklch shorter hue, #a06755 0%, #466480 100%)

tailwind v4

bg-linear-to-br/oklch from-[#a06755] to-[#466480]

Button / CTA

Open in maker →

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 −0.10 so white ink gets as close as the ±0.1 bound allows to AA on the surface and both states (worst 3.69:1). Ink is below AA (3.69:1 at the worst point) — use it for large text only, or pick a darker/lighter primary for buttons.

white 4.16 AA largeblack 3.64 AA largebanding high

Get started

hover

active

label ink below AA — large text only

css

linear-gradient(180deg in oklch shorter hue, #e63e00 0%, #c42700 100%)

tailwind v4

bg-linear-to-b/oklch from-[#e63e00] to-[#c42700]

Variants

Tonal ramp

Open in maker →

white 1.70 failsblack 3.08 AA largebanding high

css

linear-gradient(135deg in oklch shorter hue, #ffb599 0%, #fc5404 50%, #b12000 100%)

tailwind v4

bg-linear-to-br/oklch from-[#ffb599] via-[#fc5404] to-[#b12000]

Analogous

Open in maker →

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

white 3.27 AA largeblack 6.24 AAbanding high

css

linear-gradient(135deg in oklab, #fc5404 0%, #fe4179 100%)

tailwind v4

bg-linear-to-br/oklab from-[#fc5404] to-[#fe4179]

Complementary

Open in maker →

Partner hue from the complementary rule at the source colour's lightness. ΔH 180° > 140° — interpolating in oklch (shorter hue) keeps the midpoint saturated.

white 2.87 failsblack 6.33 AAbanding medium

css

linear-gradient(135deg in oklch shorter hue, #fc5404 0%, #05a6c7 100%)

tailwind v4

bg-linear-to-br/oklch from-[#fc5404] to-[#05a6c7]

Triadic

Open in maker →

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

white 2.78 failsblack 6.40 AAbanding medium

css

linear-gradient(135deg in oklab, #fc5404 0%, #06b171 100%)

tailwind v4

bg-linear-to-br/oklab from-[#fc5404] to-[#06b171]

Report — brand gradient

white ink: worst 3.28:1 at 0% (AA-large only); black ink: worst 5.18:1 at 99% (AA) → use black text.
Banding medium: ~6px bands at 1440px — add grain 9 (≈1% soft-light noise) or shorten the ramp.

Export

The custom properties below are byte-identical to the gradient block in brand.css; the DTCG token is what tokens.json carries.

css custom properties · brand.css

:root {
  /* Brand gradient (derived) */
  /* worst-case contrast: white 3.28:1 AA-large, black 5.18:1 AA */
  --brand-gradient: linear-gradient(135deg in oklch shorter hue, #fc5404 0%, #0083d5 100%);
  /* hero — worst-case contrast: white 4.60:1 AA, black 3.40:1 AA-large; ink passes AA at the worst point */
  --brand-gradient-hero: linear-gradient(135deg in oklch shorter hue, #a06755 0%, #466480 100%);
  --brand-gradient-hero-ink: #ffffff;
  /* button — worst-case contrast: white 4.16:1 AA-large, black 3.64:1 AA-large */
  --brand-gradient-button: linear-gradient(180deg in oklch shorter hue, #e63e00 0%, #c42700 100%);
  --brand-gradient-button-hover: linear-gradient(180deg in oklch shorter hue, #f14900 0%, #d22d00 100%);
  --brand-gradient-button-active: linear-gradient(180deg in oklch shorter hue, #db3200 0%, #b62200 100%);
  --brand-gradient-button-ink: #ffffff;
  /* button ink: 3.7:1 — below AA */
}

svg · brand gradient

<svg xmlns="http://www.w3.org/2000/svg" width="1440" height="600" viewBox="0 0 1440 600"><defs><linearGradient id="bs-gradient" gradientUnits="userSpaceOnUse" x1="210" y1="-210" x2="1230" y2="810"><stop offset="0%" stop-color="#fc5404"/><stop offset="7.14%" stop-color="#fa4d43"/><stop offset="14.29%" stop-color="#f64a63"/><stop offset="21.43%" stop-color="#ef4a7d"/><stop offset="28.57%" stop-color="#e54d94"/><stop offset="35.71%" stop-color="#d951a8"/><stop offset="42.86%" stop-color="#cc56ba"/><stop offset="50%" stop-color="#bd5bca"/><stop offset="57.14%" stop-color="#ac61d6"/><stop offset="64.29%" stop-color="#9a67de"/><stop offset="71.43%" stop-color="#876de3"/><stop offset="78.57%" stop-color="#7173e5"/><stop offset="85.71%" stop-color="#5979e3"/><stop offset="92.86%" stop-color="#3c7ede"/><stop offset="100%" stop-color="#0083d5"/></linearGradient></defs><rect width="1440" height="600" fill="url(#bs-gradient)"/></svg>

dtcg · tokens.json

{
  "gradient": {
    "brand": {
      "$type": "gradient",
      "$value": [
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0.988,
              0.329,
              0.016
            ],
            "hex": "#fc5404"
          },
          "position": 0
        },
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0,
              0.514,
              0.835
            ],
            "hex": "#0083d5"
          },
          "position": 1
        }
      ],
      "$extensions": {
        "com.brandsweets": {
          "kind": "linear",
          "css": "linear-gradient(135deg in oklch shorter hue, #fc5404 0%, #0083d5 100%)",
          "interpolation": "oklch",
          "hue": "shorter",
          "angle": 135,
          "name": "brand",
          "contrast": {
            "white": {
              "ratio": 3.277,
              "at": 0,
              "passesAA": false,
              "passesAALarge": true
            },
            "black": {
              "ratio": 5.183,
              "at": 0.9922,
              "passesAA": true,
              "passesAALarge": true
            },
            "suggestedInk": "#000000"
          }
        }
      },
      "$description": "The canonical brand gradient (--brand-gradient)."
    },
    "hero": {
      "$type": "gradient",
      "$value": [
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0.627,
              0.404,
              0.333
            ],
            "hex": "#a06755"
          },
          "position": 0
        },
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0.275,
              0.392,
              0.502
            ],
            "hex": "#466480"
          },
          "position": 1
        }
      ],
      "$extensions": {
        "com.brandsweets": {
          "kind": "linear",
          "css": "linear-gradient(135deg in oklch shorter hue, #a06755 0%, #466480 100%)",
          "interpolation": "oklch",
          "hue": "shorter",
          "angle": 135,
          "name": "hero",
          "ink": "#ffffff",
          "contrast": {
            "white": {
              "ratio": 4.596,
              "at": 0.0108,
              "passesAA": true,
              "passesAALarge": true
            },
            "black": {
              "ratio": 3.395,
              "at": 1,
              "passesAA": false,
              "passesAALarge": true
            },
            "suggestedInk": "#ffffff"
          }
        }
      },
      "$description": "Low-chroma hero background with a text-safe ink (--brand-gradient-hero)."
    },
    "button": {
      "$type": "gradient",
      "$value": [
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0.902,
              0.243,
              0
            ],
            "hex": "#e63e00"
          },
          "position": 0
        },
        {
          "color": {
            "colorSpace": "srgb",
            "components": [
              0.769,
              0.153,
              0
            ],
            "hex": "#c42700"
          },
          "position": 1
        }
      ],
      "$extensions": {
        "com.brandsweets": {
          "kind": "linear",
          "css": "linear-gradient(180deg in oklch shorter hue, #e63e00 0%, #c42700 100%)",
          "interpolation": "oklch",
          "hue": "shorter",
          "angle": 180,
          "name": "button",
          "ink": "#ffffff",
          "states": {
            "hover": "linear-gradient(180deg in oklch shorter hue, #f14900 0%, #d22d00 100%)",
            "active": "linear-gradient(180deg in oklch shorter hue, #db3200 0%, #b62200 100%)"
          },
          "contrast": {
            "white": {
              "ratio": 4.155,
              "at": 0,
              "passesAA": false,
              "passesAALarge": true
            },
            "black": {
              "ratio": 3.637,
              "at": 1,
              "passesAA": false,
              "passesAALarge": true
            },
            "suggestedInk": "#ffffff"
          }
        }
      },
      "$description": "Button / CTA surface with hover and active states (--brand-gradient-button)."
    }
  }
}

Colours

#fc5404 #0083d5 #ff6719

mcpConnect your agent — Substack's gradients on demand

live endpoint

Point any MCP client at the shared gradients endpoint and your agent gets the same engine as this page — make_gradient returns CSS with the interpolation space, Tailwind v4, SVG, a PNG URL, a DTCG token and the contrast report in one call; brand_gradients derives the whole contact sheet from a brand or a palette. Read-only, no key. Every gradient is a /gradients/new/… link: open it, refine, paste it back.

endpointhttps://mcp.brandsweets.com/gradients/mcp

claude mcp add --transport http brandsweets-gradients https://mcp.brandsweets.com/gradients/mcp

try this prompt

›brand_gradients for substack-com — give me the hero CSS and the ink that passes AA, then a version in oklch

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Substack and its marks belong to their owner. This page uses the name nominatively to describe gradients derived from the brand's published colour values; it does not reproduce logos or other brand assets, and it is not affiliated with or endorsed by Substack. Owner of this brand? Request a correction or removal → Machine-readable: gradients.md