# #306d9c

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

## Values

- Hex: `#306d9c`
- RGB: rgb(48, 109, 156)
- HSL: hsl(206, 53%, 40%)
- OKLCH: oklch(0.517 0.098 244.7)
- Relative luminance: 0.1397
- Nearest named color: Chill of the Night (#256d8d, Δ 2.672) — https://brandsweets.com/colors/chill-of-the-night
- Moods: cool, modern
- Page: https://brandsweets.com/colors/306d9c

## Tints & shades

- Tints (toward white): #377eb3, #448dc5, #5799cb, #6fa7d3, #86b6da, #9dc4e1, #b5d2e8, #c8deee, #e0ecf5, #f7fafd
- Shades (toward black): #2b628c, #285a81, #234f71, #1f4765, #1a3c56, #163146, #12293b, #0d1e2b, #0a161f, #050b10

## Harmonies

- Complementary: #9c5f30
- Analogous: #309c95, #30379c
- Triadic: #9c306d, #6d9c30
- Split-complementary: #9c3037, #9c9530
- Tetradic: #95309c, #9c5f30, #379c30

## Colors that go with #306d9c

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 #306d9c: softer than #000 and cool enough to feel like part of the same palette. Seen in: Amazon (https://brandsweets.com/colors/brands/amazon-com), Harbour (https://brandsweets.com/palettes/cool#harbour), Auth0 (https://brandsweets.com/colors/brands/auth0-com), Campus (https://brandsweets.com/palettes/friendly#campus). — https://brandsweets.com/colors/charcoal
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #306d9c's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Xbox (https://brandsweets.com/colors/brands/xbox-com), Motorola (https://brandsweets.com/colors/brands/motorola-com), Stripe (https://brandsweets.com/colors/brands/stripe), Slate Workspace (https://brandsweets.com/palettes/minimal#slate-workspace). — https://brandsweets.com/colors/royalblue
- **Rust** #b7410e [harmony, pool: split] — Rust is a split-complement of #306d9c: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Magazine Ochre (https://brandsweets.com/palettes/editorial#magazine-ochre), Gallery (https://brandsweets.com/palettes/editorial#gallery), Etsy (https://brandsweets.com/colors/brands/etsy-com), Semrush (https://brandsweets.com/colors/brands/semrush-com). — https://brandsweets.com/colors/rust
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #306d9c on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Dyson (https://brandsweets.com/colors/brands/dyson-com). — https://brandsweets.com/colors/sienna
- **Amber** #ffbf00 [pool] — Amber is paired with #306d9c in 8 real palettes, including Lemon Squeezy's brand system and McDonald's's brand system, as the lead colour. Seen in: 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), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 4 real palettes, including Activision's brand system and Pixar's brand system put Blue beside #306d9c, as the accent. Seen in: Activision (https://brandsweets.com/colors/brands/activision-com), Pixar (https://brandsweets.com/colors/brands/pixar-com), Tesco (https://brandsweets.com/colors/brands/tesco-com), CVS (https://brandsweets.com/colors/brands/cvs-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #306d9c: 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
- **Copper** #b87333 [pool] — Designers have shipped Copper with #306d9c: 4 real palettes, including Dusk and Desert Road, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Desert Road (https://brandsweets.com/palettes/warm#desert-road), Riverbed (https://brandsweets.com/palettes/muted#riverbed), Notion (https://brandsweets.com/colors/brands/notion). — https://brandsweets.com/colors/copper

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

- On white (#ffffff): 5.54:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #295d85 (7:1)
- On black (#000000): 3.79:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #367bb0 (4.62:1); AA: background → #e8e8e8 (4.52:1); AAA: text → #5b9bcd (7.01:1)

## 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/306d9c-9caec4-df4e56-1f212d-e9f1f1?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: "#306d9c" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.