# #666fd1

A color — cool, modern. Deterministic analysis from BrandSweets (no inference).

## Values

- Hex: `#666fd1`
- RGB: rgb(102, 111, 209)
- HSL: hsl(235, 54%, 61%)
- OKLCH: oklch(0.582 0.149 276.8)
- Relative luminance: 0.188
- Nearest named color: Flood (#6677bb, Δ 4.356) — https://brandsweets.com/colors/flood
- Moods: cool, modern
- Page: https://brandsweets.com/colors/666fd1

## Tints & shades

- Tints (toward white): #767ed6, #8189d9, #9197de, #a1a6e3, #b0b5e8, #bcc0eb, #cccff0, #dcdef4, #e7e9f8, #f7f8fd
- Shades (toward black): #4e59ca, #3b46c4, #343ead, #2d3595, #272e82, #20266a, #191d52, #12153b, #0c0e27, #050610

## Harmonies

- Complementary: #d1c866
- Analogous: #66a5d1, #9366d1
- Triadic: #d1666f, #6fd166
- Split-complementary: #d19366, #a5d166
- Tetradic: #d166a5, #d1c866, #66d193

## Colors that go with #666fd1

Named partners (harmony on the OKLCH wheel, co-occurrence in curated palettes and brand systems, and the neutrals that carry it), best first:

- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #666fd1: softer than #000 and cool enough to feel like part of the same palette. Seen in: Disney (https://brandsweets.com/colors/brands/disney-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), Hinge (https://brandsweets.com/colors/brands/hinge-co), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #666fd1 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Subaru (https://brandsweets.com/colors/brands/subaru-com), Next.js (https://brandsweets.com/colors/brands/nextjs-org), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Netflix (https://brandsweets.com/colors/brands/netflix). — https://brandsweets.com/colors/seagreen
- **Amber** #ffbf00 [pool] — Amber is paired with #666fd1 in 12 real palettes, including Wikipedia's brand system and Mastodon hosted on mastodon.social's brand system, as the accent. Seen in: Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org), Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), Google (https://brandsweets.com/colors/brands/google-com), Walmart (https://brandsweets.com/colors/brands/walmart-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 14 real palettes, including Qualcomm's brand system and Pixar's brand system put Blue beside #666fd1, as the accent. Seen in: Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Pixar (https://brandsweets.com/colors/brands/pixar-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), BBC (https://brandsweets.com/colors/brands/bbc-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #666fd1: 10 real palettes, including Carrefour's brand system and Intel's brand system, as the accent. Seen in: Carrefour (https://brandsweets.com/colors/brands/carrefour-com), Intel (https://brandsweets.com/colors/brands/intel-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com), Hershey's (https://brandsweets.com/colors/brands/hersheys-com). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #666fd1: 6 real palettes, including Mastodon hosted on mastodon.social's brand system and Coca-Cola's brand system, as the supporting colour. Seen in: Mastodon hosted on mastodon.social (https://brandsweets.com/colors/brands/mastodon-social), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), NBA (https://brandsweets.com/colors/brands/nba-com), Webflow (https://brandsweets.com/colors/brands/webflow-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #666fd1 in 15 real palettes, including Marvel's brand system and Pizza Hut's brand system, as the accent. Seen in: Marvel (https://brandsweets.com/colors/brands/marvel-com), Pizza Hut (https://brandsweets.com/colors/brands/pizzahut-com), Netflix (https://brandsweets.com/colors/brands/netflix), Ulta Beauty (https://brandsweets.com/colors/brands/ulta-com). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #666fd1: 8 real palettes, including Calm's brand system and Astro's brand system, as the lead colour. Seen in: Calm (https://brandsweets.com/colors/brands/calm-com), Astro (https://brandsweets.com/colors/brands/astro-build), Patreon (https://brandsweets.com/colors/brands/patreon-com), Venmo (https://brandsweets.com/colors/brands/venmo-com). — https://brandsweets.com/colors/deepskyblue

## Contrast (WCAG 2.x, as text)

- On white (#ffffff): 4.41:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #626bd0 (4.63:1); AA: background → #080808 (4.54:1); AAA: text → #3b46c4 (7.34:1)
- On black (#000000): 4.76:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #8990dc (7.09:1)

## Brands using this color

- **Linear** — primary #5e6ad2 (Δ 1.809) — https://brandsweets.com/colors/brands/linear
- **Brilliant** — accent #5d74cc (Δ 1.904) — https://brandsweets.com/colors/brands/brilliant-org

## Fonts for this mood

- modern: https://brandsweets.com/fonts/mood/modern

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/666fd1-9e9cc4-df8d4e-241f2d-e9eef1?lock=0&style=vibrant
(Humans lock/regenerate in the tool; the URL is the state — read `lock=` back to see what they kept.)

## Connect an agent

Point any MCP client at the BrandSweets colors endpoint for the same engine:

- Endpoint: https://mcp.brandsweets.com/colors/mcp
- Tools: `analyze_color` (e.g. `analyze_color({ color: "#666fd1" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.