# #307d9c

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

## Values

- Hex: `#307d9c`
- RGB: rgb(48, 125, 156)
- HSL: hsl(197, 53%, 40%)
- OKLCH: oklch(0.556 0.088 228.3)
- Relative luminance: 0.177
- Nearest named color: Cry Me a River (#427898, Δ 1.819) — https://brandsweets.com/colors/cry-me-a-river
- Moods: cool, modern
- Page: https://brandsweets.com/colors/307d9c

## Tints & shades

- Tints (toward white): #3790b3, #44a1c5, #57abcb, #6fb6d3, #86c2da, #9dcee1, #b5dae8, #c8e3ee, #e0eff5, #f7fbfd
- Shades (toward black): #2b718c, #286781, #235b71, #1f5265, #1a4556, #163846, #122f3b, #0d222b, #0a191f, #050d10

## Harmonies

- Complementary: #9c4f30
- Analogous: #309c85, #30479c
- Triadic: #9c307d, #7d9c30
- Split-complementary: #9c3047, #9c8530
- Tetradic: #85309c, #9c4f30, #479c30

## Colors that go with #307d9c

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 #307d9c: softer than #000 and cool enough to feel like part of the same palette. Seen in: Auth0 (https://brandsweets.com/colors/brands/auth0-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Campus (https://brandsweets.com/palettes/friendly#campus), Gusto (https://brandsweets.com/colors/brands/gusto-com). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [harmony, pool: split] — Crimson is a split-complement of #307d9c: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Redfin (https://brandsweets.com/colors/brands/redfin-com), NASCAR (https://brandsweets.com/colors/brands/nascar-com). — https://brandsweets.com/colors/crimson
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #307d9c's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Slate Workspace (https://brandsweets.com/palettes/minimal#slate-workspace), Stripe (https://brandsweets.com/colors/brands/stripe), Xbox (https://brandsweets.com/colors/brands/xbox-com), GitHub (https://brandsweets.com/colors/brands/github). — https://brandsweets.com/colors/royalblue
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #307d9c 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 #307d9c in 8 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
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #307d9c: 7 real palettes, including Glacier and Hershey's's brand system, as the accent. Seen in: Glacier (https://brandsweets.com/palettes/cool#glacier), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #307d9c: 5 real palettes, including Riverbed and Dusk, as the accent. Seen in: Riverbed (https://brandsweets.com/palettes/muted#riverbed), Dusk (https://brandsweets.com/palettes/cool#dusk), Notion (https://brandsweets.com/colors/brands/notion), Wellness (https://brandsweets.com/palettes/warm#wellness). — https://brandsweets.com/colors/copper
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #307d9c: 5 real palettes, including Deep Water and Venmo's brand system, as the lead colour. Seen in: Deep Water (https://brandsweets.com/palettes/dark#deep-water), Venmo (https://brandsweets.com/colors/brands/venmo-com), Astro (https://brandsweets.com/colors/brands/astro-build), Telegram (https://brandsweets.com/colors/brands/telegram-org). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 4.63:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #245e75 (7.16:1)
- On black (#000000): 4.54:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #44a1c5 (7.15:1)

## Curated palettes containing it

- **Retro Pop** (playful, bold, warm) — #e63946, #457b9d, #f4a261, #fff4e0, #23201c — Fifties-diner red and steel blue with a peach — nostalgic pop that still passes contrast. — tool: https://brandsweets.com/palettes/new/e63946-457b9d-f4a261-fff4e0-23201c — collection: https://brandsweets.com/palettes/playful

## 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/307d9c-9cb4c4-df4e6b-1f232d-e9f1ef?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: "#307d9c" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.