# #309bb5

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

## Values

- Hex: `#309bb5`
- RGB: rgb(48, 155, 181)
- HSL: hsl(192, 58%, 45%)
- OKLCH: oklch(0.641 0.101 217.8)
- Relative luminance: 0.2741
- Nearest named color: Blue Ocean (#009dc4, Δ 2.361) — https://brandsweets.com/colors/blue-ocean
- Moods: cool, modern
- Page: https://brandsweets.com/colors/309bb5

## Tints & shades

- Tints (toward white): #36acc9, #4eb6d0, #62bed5, #76c6db, #8ed0e1, #a2d9e6, #b6e1ec, #cbe9f1, #e3f3f8, #f7fcfd
- Shades (toward black): #2c8da5, #287f95, #237185, #1f6475, #1b5665, #154551, #113740, #0d2930, #091b20, #040e10

## Harmonies

- Complementary: #b54b30
- Analogous: #30b58d, #3058b5
- Triadic: #b5309b, #9bb530
- Split-complementary: #b53058, #b58d30
- Tetradic: #8d30b5, #b54b30, #58b530

## Colors that go with #309bb5

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 #309bb5: softer than #000 and cool enough to feel like part of the same palette. Seen in: Lido (https://brandsweets.com/palettes/vivid#lido), Dusty Blue (https://brandsweets.com/palettes/cool#dusty-blue), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Coastal (https://brandsweets.com/palettes/cool#coastal). — https://brandsweets.com/colors/charcoal
- **Orange Red** #ff4500 [harmony, pool: complementary] — Orange Red sits directly opposite #309bb5 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), Figma (https://brandsweets.com/colors/brands/figma). — https://brandsweets.com/colors/orangered
- **Amber** #ffbf00 [pool] — Amber is paired with #309bb5 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), Salesforce (https://brandsweets.com/colors/brands/salesforce-com), Lemon Squeezy (https://brandsweets.com/colors/brands/lemonsqueezy-com). — https://brandsweets.com/colors/amber
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #309bb5: 4 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), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #309bb5: 4 real palettes, including Dusk and Notion's brand system, as the accent. Seen in: Dusk (https://brandsweets.com/palettes/cool#dusk), Notion (https://brandsweets.com/colors/brands/notion), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty), Atelier (https://brandsweets.com/palettes/elegant#atelier). — https://brandsweets.com/colors/copper
- **Crimson** #dc143c [pool] — Crimson is paired with #309bb5 in 6 real palettes, including Diner and Retro Pop, as the lead colour. Seen in: Diner (https://brandsweets.com/palettes/vivid#diner), Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), Redfin (https://brandsweets.com/colors/brands/redfin-com), NASCAR (https://brandsweets.com/colors/brands/nascar-com). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #309bb5: 6 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 #309bb5: 10 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), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com). — https://brandsweets.com/colors/denim

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

- On white (#ffffff): 3.24:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #287f95 (4.61:1); AA: background → #262626 (4.67:1); AAA: text → #1e6071 (7.08:1)
- On black (#000000): 6.48:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #32a2bd (7.04:1)

## 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/309bb5-a2b5be-df4e77-1f242d-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: "#309bb5" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.