# #307fb0

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

## Values

- Hex: `#307fb0`
- RGB: rgb(48, 127, 176)
- HSL: hsl(203, 57%, 44%)
- OKLCH: oklch(0.571 0.107 239.9)
- Relative luminance: 0.1894
- Nearest named color: steelblue (#4682b4, Δ 2.17) — https://brandsweets.com/colors/steelblue
- Moods: cool, modern
- Page: https://brandsweets.com/colors/307fb0

## Tints & shades

- Tints (toward white): #368ec4, #4b9cce, #5fa7d3, #77b4da, #8bbfdf, #9fcae5, #b7d7eb, #cbe2f1, #e3f0f7, #f7fbfd
- Shades (toward black): #2c74a0, #276890, #235c80, #1f5170, #1a4560, #163a50, #122e40, #0d2330, #091720, #040c10

## Harmonies

- Complementary: #b06130
- Analogous: #30b0a1, #303fb0
- Triadic: #b0307f, #7fb030
- Split-complementary: #b0303f, #b0a130
- Tetradic: #a130b0, #b06130, #3fb030

## Colors that go with #307fb0

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 #307fb0: 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), Plaid (https://brandsweets.com/colors/brands/plaid-com), Campus (https://brandsweets.com/palettes/friendly#campus). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [harmony, pool: split] — Crimson is a split-complement of #307fb0: 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), NASCAR (https://brandsweets.com/colors/brands/nascar-com), State Farm (https://brandsweets.com/colors/brands/statefarm-com). — https://brandsweets.com/colors/crimson
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #307fb0'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), Guinness (https://brandsweets.com/colors/brands/guinness-com), Stripe (https://brandsweets.com/colors/brands/stripe), Chase (https://brandsweets.com/colors/brands/chase-com). — https://brandsweets.com/colors/royalblue
- **Copper** #b87333 [harmony, pool: complementary] — Copper sits directly opposite #307fb0 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Notion (https://brandsweets.com/colors/brands/notion), Dusk (https://brandsweets.com/palettes/cool#dusk), Riverbed (https://brandsweets.com/palettes/muted#riverbed). — https://brandsweets.com/colors/copper
- **Amber** #ffbf00 [pool] — Amber is paired with #307fb0 in 9 real palettes, including Beach Hut and Wired's brand system, as the supporting colour. Seen in: Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Wired (https://brandsweets.com/colors/brands/wired-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 6 real palettes, including Activision's brand system and Readymag's brand system put Blue beside #307fb0, as the accent. Seen in: Activision (https://brandsweets.com/colors/brands/activision-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Pixar (https://brandsweets.com/colors/brands/pixar-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #307fb0: 8 real palettes, including Hershey's's brand system and Glacier, as the supporting colour. Seen in: Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Glacier (https://brandsweets.com/palettes/cool#glacier), General Mills (https://brandsweets.com/colors/brands/generalmills-com), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/cobalt
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #307fb0: 5 real palettes, including Deep Water and Astro's brand system, as the lead colour. Seen in: Deep Water (https://brandsweets.com/palettes/dark#deep-water), Astro (https://brandsweets.com/colors/brands/astro-build), Telegram (https://brandsweets.com/colors/brands/telegram-org), Venmo (https://brandsweets.com/colors/brands/venmo-com). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 4.39:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #2f7cac (4.57:1); AA: background → #0a0a0a (4.51:1); AAA: text → #235c80 (7.21:1)
- On black (#000000): 4.79:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #4f9ecf (7.12:1)

## 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/307fb0-9cb0c4-df4e5d-1f222d-e9f1f0?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: "#307fb0" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.