# #307f9c

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

## Values

- Hex: `#307f9c`
- RGB: rgb(48, 127, 156)
- HSL: hsl(196, 53%, 40%)
- OKLCH: oklch(0.561 0.088 226.1)
- Relative luminance: 0.1821
- Nearest named color: Ahoy! Blue (#0082a1, Δ 1.772) — https://brandsweets.com/colors/ahoy-blue
- Moods: cool, modern
- Page: https://brandsweets.com/colors/307f9c

## Tints & shades

- Tints (toward white): #3792b3, #44a3c5, #57accb, #6fb8d3, #86c4da, #9dcfe1, #b5dbe8, #c8e4ee, #e0f0f5, #f7fbfd
- Shades (toward black): #2b738c, #286981, #235c71, #1f5365, #1a4656, #163946, #12303b, #0d232b, #0a191f, #050d10

## Harmonies

- Complementary: #9c4d30
- Analogous: #309c83, #30499c
- Triadic: #9c307f, #7f9c30
- Split-complementary: #9c3049, #9c8330
- Tetradic: #83309c, #9c4d30, #499c30

## Colors that go with #307f9c

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 #307f9c: softer than #000 and cool enough to feel like part of the same palette. Seen in: Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Auth0 (https://brandsweets.com/colors/brands/auth0-com), Campus (https://brandsweets.com/palettes/friendly#campus), Gusto (https://brandsweets.com/colors/brands/gusto-com). — https://brandsweets.com/colors/charcoal
- **Copper** #b87333 [harmony, pool: split] — Copper is a split-complement of #307f9c: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Riverbed (https://brandsweets.com/palettes/muted#riverbed), Dusk (https://brandsweets.com/palettes/cool#dusk), Wellness (https://brandsweets.com/palettes/warm#wellness), Notion (https://brandsweets.com/colors/brands/notion). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [harmony, pool: split] — Crimson is a split-complement of #307f9c: 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), Redfin (https://brandsweets.com/colors/brands/redfin-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com), NASCAR (https://brandsweets.com/colors/brands/nascar-com). — https://brandsweets.com/colors/crimson
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #307f9c'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), GitHub (https://brandsweets.com/colors/brands/github), Guinness (https://brandsweets.com/colors/brands/guinness-com). — https://brandsweets.com/colors/royalblue
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #307f9c 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 #307f9c in 7 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 #307f9c: 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
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #307f9c: 5 real palettes, including Deep Water and Telegram's brand system, as the lead colour. Seen in: Deep Water (https://brandsweets.com/palettes/dark#deep-water), Telegram (https://brandsweets.com/colors/brands/telegram-org), Astro (https://brandsweets.com/colors/brands/astro-build), Venmo (https://brandsweets.com/colors/brands/venmo-com). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 4.52:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #245f75 (7.07:1)
- On black (#000000): 4.64:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #40a1c4 (7.11:1)

## 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/307f9c-9cb5c4-df4e6e-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: "#307f9c" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.