# #666d8a

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

## Values

- Hex: `#666d8a`
- RGB: rgb(102, 109, 138)
- HSL: hsl(228, 15%, 47%)
- OKLCH: oklch(0.54 0.046 274.2)
- Relative luminance: 0.156
- Nearest named color: Dark Prince (#6b6c89, Δ 0.745) — https://brandsweets.com/colors/dark-prince
- Moods: cool, muted
- Page: https://brandsweets.com/colors/666d8a

## Tints & shades

- Tints (toward white): #727a97, #8187a2, #9095ad, #9ea3b7, #b0b4c4, #bec2cf, #cdd0da, #dcdee5, #eaecf0, #f9f9fb
- Shades (toward black): #5d647e, #52586f, #4a4f64, #414658, #383c4c, #2e313e, #252732, #1c1e26, #111317, #09090c

## Harmonies

- Complementary: #8a8366
- Analogous: #667f8a, #71668a
- Triadic: #8a666d, #6d8a66
- Split-complementary: #8a7166, #7f8a66
- Tetradic: #8a667f, #8a8366, #668a71

## Colors that go with #666d8a

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 #666d8a: 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 #666d8a — 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 #666d8a 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 #666d8a 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), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Wired (https://brandsweets.com/colors/brands/wired-com). — https://brandsweets.com/colors/amber
- **Champagne** #f7e7ce [pool] — 6 real palettes, including Coffee Bar and Midnight Luxe put Champagne beside #666d8a, as that palette's text colour. Seen in: Coffee Bar (https://brandsweets.com/palettes/dark#coffee-bar), Midnight Luxe (https://brandsweets.com/palettes/luxury#midnight-luxe), BrandSweets (https://brandsweets.com/colors/brands/brandsweets), Forest Floor (https://brandsweets.com/palettes/dark#forest-floor). — https://brandsweets.com/colors/champagne
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #666d8a: 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 #666d8a: 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), Desert Road (https://brandsweets.com/palettes/warm#desert-road), Atelier (https://brandsweets.com/palettes/elegant#atelier). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #666d8a in 11 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): 5.1:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #52586f (7.04:1)
- On black (#000000): 4.12:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #6c7493 (4.56:1); AA: background → #f2f2f2 (4.55:1); AAA: text → #9095ad (7.09:1)

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/666d8a-9c9fc4-df7c4e-231f2d-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: "#666d8a" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.