# #666e8a

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

## Values

- Hex: `#666e8a`
- RGB: rgb(102, 110, 138)
- HSL: hsl(227, 15%, 47%)
- OKLCH: oklch(0.542 0.045 272.4)
- Relative luminance: 0.1581
- Nearest named color: Dark Prince (#6b6c89, Δ 0.854) — https://brandsweets.com/colors/dark-prince
- Moods: cool, muted
- Page: https://brandsweets.com/colors/666e8a

## Tints & shades

- Tints (toward white): #727a97, #8188a2, #9096ad, #9ea4b7, #b0b4c4, #bec2cf, #cdd0da, #dcdee5, #eaecf0, #f9f9fb
- Shades (toward black): #5d647e, #52596f, #4a4f64, #414658, #383d4c, #2e313e, #252832, #1c1e26, #111317, #09090c

## Harmonies

- Complementary: #8a8266
- Analogous: #66808a, #70668a
- Triadic: #8a666e, #6e8a66
- Split-complementary: #8a7066, #808a66
- Tetradic: #8a6680, #8a8266, #668a70

## Colors that go with #666e8a

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 #666e8a: softer than #000 and cool enough to feel like part of the same palette. Seen in: Campus (https://brandsweets.com/palettes/friendly#campus), Bloomberg (https://brandsweets.com/colors/brands/bloomberg-com), Hermès (https://brandsweets.com/colors/brands/hermes-com), PlayStation® Official Site: Consoles, Games, Accessories & MoreSony Interactive Entertainment (https://brandsweets.com/colors/brands/playstation-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #666e8a — 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), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Mushroom (https://brandsweets.com/palettes/neutral#mushroom), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com). — https://brandsweets.com/colors/seagreen
- **Dark Olive Green** #556b2f [harmony, pool: complementary] — Dark Olive Green sits directly opposite #666e8a on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Magazine Ochre (https://brandsweets.com/palettes/editorial#magazine-ochre). — https://brandsweets.com/colors/darkolivegreen
- **Amber** #ffbf00 [pool] — Amber is paired with #666e8a in 5 real palettes, including Beach Hut and Lemon Squeezy's brand system, as the supporting colour. Seen in: Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Wired (https://brandsweets.com/colors/brands/wired-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com). — https://brandsweets.com/colors/amber
- **Champagne** #f7e7ce [pool] — 6 real palettes, including Midnight Luxe and Coffee Bar put Champagne beside #666e8a, as that palette's text colour. Seen in: Midnight Luxe (https://brandsweets.com/palettes/luxury#midnight-luxe), Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar), Forest Floor (https://brandsweets.com/palettes/dark#forest-floor), BrandSweets (https://brandsweets.com/colors/brands/brandsweets). — https://brandsweets.com/colors/champagne
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #666e8a: 6 real palettes, including Ink & Paper and Fintech Trust, as the accent. Seen in: Ink & Paper (https://brandsweets.com/palettes/minimal#ink-and-paper), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Glacier (https://brandsweets.com/palettes/cool#glacier), Hershey's (https://brandsweets.com/colors/brands/hersheys-com). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #666e8a: 6 real palettes, including Dusk and Riverbed, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Riverbed (https://brandsweets.com/palettes/muted#riverbed), Atelier (https://brandsweets.com/palettes/elegant#atelier), Desert Road (https://brandsweets.com/palettes/warm#desert-road). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #666e8a in 10 real palettes, including Retro Pop and Wendy's's brand system, as the lead colour. Seen in: Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Redfin (https://brandsweets.com/colors/brands/redfin-com). — https://brandsweets.com/colors/crimson

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

- On white (#ffffff): 5.05:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #50566d (7.26:1)
- On black (#000000): 4.16:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #6c7593 (4.6:1); AA: background → #f2f2f2 (4.51:1); AAA: text → #9096ad (7.15:1)

## Curated palettes containing it

- **Slate Workspace** (minimal, cool, clean, modern) — #0f172a, #64748b, #2563eb, #f8fafc — Slate on slate with a single blue — the productivity-app look where the interface disappears behind the work. — tool: https://brandsweets.com/palettes/new/0f172a-64748b-2563eb-f8fafc — collection: https://brandsweets.com/palettes/minimal
- **Clinic** (clean, cool, light) — #0e7490, #64748b, #f97316, #f8fafc, #0f172a — Teal reads clinical without the coldness of pure blue; the coral accent adds warmth for reassurance moments. — tool: https://brandsweets.com/palettes/new/0e7490-64748b-f97316-f8fafc-0f172a — collection: https://brandsweets.com/palettes/clean
- **Campus** (friendly, cool, clean) — #1d4ed8, #64748b, #f59e0b, #ffffff, #1e293b — Institutional blue with a highlighter-amber accent — trustworthy for parents, lively enough for students. — tool: https://brandsweets.com/palettes/new/1d4ed8-64748b-f59e0b-ffffff-1e293b — collection: https://brandsweets.com/palettes/friendly

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/666e8a-9ca0c4-df7a4e-221f2d-e9eff1?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: "#666e8a" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.