# #309db5

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

## Values

- Hex: `#309db5`
- RGB: rgb(48, 157, 181)
- HSL: hsl(191, 58%, 45%)
- OKLCH: oklch(0.646 0.101 215.9)
- Relative luminance: 0.2808
- Nearest named color: Blue Ocean (#009dc4, Δ 2.499) — https://brandsweets.com/colors/blue-ocean
- Moods: cool, modern
- Page: https://brandsweets.com/colors/309db5

## Tints & shades

- Tints (toward white): #36aec9, #4eb8d0, #62c0d5, #76c8db, #8ed2e1, #a2dae6, #b6e2ec, #cbeaf1, #e3f4f8, #f7fcfd
- Shades (toward black): #2c8fa5, #288195, #237385, #1f6575, #1b5765, #154651, #113840, #0d2a30, #091c20, #040e10

## Harmonies

- Complementary: #b54930
- Analogous: #30b58b, #305ab5
- Triadic: #b5309d, #9db530
- Split-complementary: #b5305a, #b58b30
- Tetradic: #8b30b5, #b54930, #5ab530

## Colors that go with #309db5

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 #309db5: 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), Dusty Blue (https://brandsweets.com/palettes/cool#dusty-blue), Tide Pool (https://brandsweets.com/palettes/cool#tide-pool). — https://brandsweets.com/colors/charcoal
- **Orange Red** #ff4500 [harmony, pool: complementary] — Orange Red sits directly opposite #309db5 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 #309db5 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), Blueprint (https://brandsweets.com/palettes/technical#blueprint). — https://brandsweets.com/colors/amber
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #309db5: 4 real palettes, including Hershey's's brand system and Fintech Trust, as the supporting colour. Seen in: Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/cobalt
- **Copper** #b87333 [pool] — Designers have shipped Copper with #309db5: 4 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), Notion (https://brandsweets.com/colors/brands/notion), Atelier (https://brandsweets.com/palettes/elegant#atelier). — https://brandsweets.com/colors/copper
- **Cornflower Blue** #6495ed [harmony, pool: analogous] — Cornflower Blue is #309db5's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Arctic (https://brandsweets.com/palettes/clean#arctic), Canva (https://brandsweets.com/colors/brands/canva-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #309db5 in 6 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), 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 #309db5: 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), Figma (https://brandsweets.com/colors/brands/figma). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 3.17:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #288195 (4.5:1); AA: background → #292929 (4.58:1); AAA: text → #1d5e6d (7.31:1)
- On black (#000000): 6.62:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #32a4bd (7.18:1)

## 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/309db5-a2b6be-df4e7a-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: "#309db5" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.