# #309bb0

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

## Values

- Hex: `#309bb0`
- RGB: rgb(48, 155, 176)
- HSL: hsl(190, 57%, 44%)
- OKLCH: oklch(0.639 0.098 213.7)
- Relative luminance: 0.2721
- Nearest named color: Blue Moon (#3992a8, Δ 2.536) — https://brandsweets.com/colors/blue-moon
- Moods: cool, modern
- Page: https://brandsweets.com/colors/309bb0

## Tints & shades

- Tints (toward white): #36acc4, #4bb8ce, #5fc0d3, #77c9da, #8bd1df, #9fd9e5, #b7e3eb, #cbeaf1, #e3f4f7, #f7fcfd
- Shades (toward black): #2c8da0, #277f90, #237180, #1f6370, #1a5460, #164650, #123840, #0d2a30, #091c20, #040e10

## Harmonies

- Complementary: #b04630
- Analogous: #30b086, #305bb0
- Triadic: #b0309b, #9bb030
- Split-complementary: #b0305b, #b08630
- Tetradic: #8630b0, #b04630, #5bb030

## Colors that go with #309bb0

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 #309bb0: softer than #000 and cool enough to feel like part of the same palette. Seen in: Lido (https://brandsweets.com/palettes/vivid#lido), Coastal (https://brandsweets.com/palettes/cool#coastal), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool), Dusty Blue (https://brandsweets.com/palettes/cool#dusty-blue). — https://brandsweets.com/colors/charcoal
- **Orange Red** #ff4500 [harmony, pool: complementary] — Orange Red sits directly opposite #309bb0 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Launch Orange (https://brandsweets.com/palettes/bold#launch-orange), Cursor (https://brandsweets.com/colors/brands/cursor-com), Substack (https://brandsweets.com/colors/brands/substack-com). — https://brandsweets.com/colors/orangered
- **Amber** #ffbf00 [pool] — Amber is paired with #309bb0 in 4 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), Salesforce (https://brandsweets.com/colors/brands/salesforce-com). — https://brandsweets.com/colors/amber
- **Copper** #b87333 [pool] — Designers have shipped Copper with #309bb0: 6 real palettes, including Dusk and Clean Beauty, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty), Atelier (https://brandsweets.com/palettes/elegant#atelier), Notion (https://brandsweets.com/colors/brands/notion). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #309bb0 in 5 real palettes, including Diner and Redfin's brand system, as the lead colour. Seen in: Diner (https://brandsweets.com/palettes/vivid#diner), Redfin (https://brandsweets.com/colors/brands/redfin-com), Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Wendy's (https://brandsweets.com/colors/brands/wendys-com). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #309bb0: 5 real palettes, including Telegram's brand system and Snowflake AI Data Cloud's brand system, as the lead colour. Seen in: Telegram (https://brandsweets.com/colors/brands/telegram-org), Snowflake AI Data Cloud (https://brandsweets.com/colors/brands/snowflake-com), Remix (https://brandsweets.com/colors/brands/remix-run), Astro (https://brandsweets.com/colors/brands/astro-build). — https://brandsweets.com/colors/deepskyblue
- **Denim** #1560bd [pool] — Designers have shipped Denim with #309bb0: 9 real palettes, including Gopro's brand system and Peacock, as the lead colour. Seen in: Gopro (https://brandsweets.com/colors/brands/gopro-com), Peacock (https://brandsweets.com/palettes/vivid#peacock), Dusk (https://brandsweets.com/palettes/cool#dusk), Open House (https://brandsweets.com/palettes/clean#open-house). — https://brandsweets.com/colors/denim
- **Midnight Blue** #191970 [pool] — 10 real palettes, including Ford's brand system and SoFi's brand system put Midnight Blue beside #309bb0, as the lead colour. Seen in: Ford (https://brandsweets.com/colors/brands/ford-com), SoFi (https://brandsweets.com/colors/brands/sofi-com), Confluent (https://brandsweets.com/colors/brands/confluent-io), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool). — https://brandsweets.com/colors/midnightblue

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

- On white (#ffffff): 3.26:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #277f90 (4.64:1); AA: background → #262626 (4.64:1); AAA: text → #1e5f6c (7.22:1)
- On black (#000000): 6.44:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #34a5bc (7.25:1)

## 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/309bb0-a2b6be-df4e7c-1f252d-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: "#309bb0" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.