# #666ba3

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

## Values

- Hex: `#666ba3`
- RGB: rgb(102, 107, 163)
- HSL: hsl(235, 25%, 52%)
- OKLCH: oklch(0.547 0.087 279.2)
- Relative luminance: 0.1598
- Nearest named color: Loch Ness (#5f6db0, Δ 2.147) — https://brandsweets.com/colors/loch-ness
- Moods: cool, muted
- Page: https://brandsweets.com/colors/666ba3

## Tints & shades

- Tints (toward white): #767bad, #8387b4, #9396be, #9fa3c6, #afb2cf, #bfc1d9, #cccee0, #dcddea, #e9e9f2, #f9f9fb
- Shades (toward black): #5a5f96, #505586, #494d79, #3f4369, #363959, #2c2e49, #222439, #1b1c2d, #11121d, #08080d

## Harmonies

- Complementary: #a39e66
- Analogous: #668aa3, #8066a3
- Triadic: #a3666b, #6ba366
- Split-complementary: #a38066, #8aa366
- Tetradic: #a3668a, #a39e66, #66a380

## Colors that go with #666ba3

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 #666ba3: softer than #000 and cool enough to feel like part of the same palette. Seen in: Campus (https://brandsweets.com/palettes/friendly#campus), Plaid (https://brandsweets.com/colors/brands/plaid-com), Bloomberg (https://brandsweets.com/colors/brands/bloomberg-com), Hermès (https://brandsweets.com/colors/brands/hermes-com). — https://brandsweets.com/colors/charcoal
- **Amber** #ffbf00 [pool] — Amber is paired with #666ba3 in 8 real palettes, including Lemon Squeezy's brand system and Warner Bros.'s brand system, as the lead colour. Seen in: Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com), Wired (https://brandsweets.com/colors/brands/wired-com). — https://brandsweets.com/colors/amber
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #666ba3: 7 real palettes, including Fintech Trust and Glacier, as the lead colour. Seen in: 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), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #666ba3 in 15 real palettes, including Marvel's brand system and Retro Pop, as the accent. Seen in: Marvel (https://brandsweets.com/colors/brands/marvel-com), Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Netflix (https://brandsweets.com/colors/brands/netflix). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #666ba3: 5 real palettes, including Astro's brand system and Deep Water, as the supporting colour. Seen in: Astro (https://brandsweets.com/colors/brands/astro-build), Deep Water (https://brandsweets.com/palettes/dark#deep-water), Venmo (https://brandsweets.com/colors/brands/venmo-com), Calm (https://brandsweets.com/colors/brands/calm-com). — https://brandsweets.com/colors/deepskyblue
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #666ba3: 6 real palettes, including Honda's brand system and AT&T's brand system, as the supporting colour. Seen in: Honda (https://brandsweets.com/colors/brands/honda-com), AT&T (https://brandsweets.com/colors/brands/att-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Campbell's (https://brandsweets.com/colors/brands/campbells-com). — https://brandsweets.com/colors/firebrick
- **Goldenrod** #daa520 [pool] — Goldenrod shows up next to #666ba3 in 6 real palettes, including Open House and Sapphire & Gold, as the accent. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Ledger Dark (https://brandsweets.com/palettes/dark#ledger-dark), Chevrolet (https://brandsweets.com/colors/brands/chevrolet-com). — https://brandsweets.com/colors/goldenrod
- **Dark Olive Green** #556b2f [harmony: complementary] — Dark Olive Green sits directly opposite #666ba3 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/darkolivegreen

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

- On white (#ffffff): 5:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #505586 (7.04:1)
- On black (#000000): 4.2:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #6c71a7 (4.56:1); AA: background → #f5f5f5 (4.59:1); AAA: text → #8f93bc (7.07:1)

## Palette tool

Open this color locked as the lead with four explored companions: https://brandsweets.com/palettes/new/666ba3-9e9cc4-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: "#666ba3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.