# #309fcf

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

## Values

- Hex: `#309fcf`
- RGB: rgb(48, 159, 207)
- HSL: hsl(198, 62%, 50%)
- OKLCH: oklch(0.662 0.119 231.7)
- Relative luminance: 0.2993
- Nearest named color: Blue Burst (#309cd0, Δ 0.914) — https://brandsweets.com/colors/blue-burst
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/309fcf

## Tints & shades

- Tints (toward white): #45a9d3, #5ab2d8, #6abadc, #7fc4e1, #94cde6, #a8d7eb, #bde0ef, #cde8f3, #e2f2f8, #f7fbfd
- Shades (toward black): #2c8fba, #2882a9, #237395, #1f6684, #1a5670, #15465b, #11394a, #0d2936, #091d25, #040d11

## Harmonies

- Complementary: #cf6030
- Analogous: #30cfaf, #3050cf
- Triadic: #cf309f, #9fcf30
- Split-complementary: #cf3050, #cfaf30
- Tetradic: #af30cf, #cf6030, #50cf30

## Colors that go with #309fcf

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 #309fcf: softer than #000 and cool enough to feel like part of the same palette. Seen in: Lido (https://brandsweets.com/palettes/vivid#lido), Lamborghini (https://brandsweets.com/colors/brands/lamborghini-com), Lagoon (https://brandsweets.com/palettes/vivid#lagoon), Dusty Blue (https://brandsweets.com/palettes/cool#dusty-blue). — https://brandsweets.com/colors/charcoal
- **Tomato** #ff6347 [harmony, pool: split] — Tomato is a split-complement of #309fcf: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Lido (https://brandsweets.com/palettes/vivid#lido), Substack (https://brandsweets.com/colors/brands/substack-com), Hermès (https://brandsweets.com/colors/brands/hermes-com), Replit (https://brandsweets.com/colors/brands/replit). — https://brandsweets.com/colors/tomato
- **Amber** #ffbf00 [pool] — Amber is paired with #309fcf in 8 real palettes, including Salesforce's brand system and Beach Hut, as the accent. Seen in: Salesforce (https://brandsweets.com/colors/brands/salesforce-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), NBA (https://brandsweets.com/colors/brands/nba-com), Heatwave (https://brandsweets.com/palettes/warm#heatwave). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 5 real palettes, including Unity's brand system and Qualcomm's brand system put Blue beside #309fcf, as the supporting colour. Seen in: Unity (https://brandsweets.com/colors/brands/unity-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), Warp (https://brandsweets.com/colors/brands/warp-dev). — https://brandsweets.com/colors/blue
- **Crimson** #dc143c [pool] — Crimson is paired with #309fcf in 4 real palettes, including Diner and Riot Games's brand system, as the lead colour. Seen in: Diner (https://brandsweets.com/palettes/vivid#diner), Riot Games (https://brandsweets.com/colors/brands/riotgames-com), NASCAR (https://brandsweets.com/colors/brands/nascar-com), Retro Pop (https://brandsweets.com/palettes/playful#retro-pop). — https://brandsweets.com/colors/crimson
- **Dark Orange** #ff8c00 [pool] — Dark Orange shows up next to #309fcf in 4 real palettes, including Elastic's brand system and Learning App, as the lead colour. Seen in: Elastic (https://brandsweets.com/colors/brands/elastic-co), Learning App (https://brandsweets.com/palettes/playful#learning-app), Playground (https://brandsweets.com/palettes/bold#playground), Ahrefs (https://brandsweets.com/colors/brands/ahrefs-com). — https://brandsweets.com/colors/darkorange
- **Denim** #1560bd [pool] — Designers have shipped Denim with #309fcf: 12 real palettes, including Gopro's brand system and Coca-Cola's brand system, as the lead colour. Seen in: Gopro (https://brandsweets.com/colors/brands/gopro-com), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com), Apple (https://brandsweets.com/colors/brands/apple-com), Venmo (https://brandsweets.com/colors/brands/venmo-com). — https://brandsweets.com/colors/denim
- **Light Sky Blue** #87cefa [pool] — Light Sky Blue is paired with #309fcf in 4 real palettes, including Calm's brand system and Salesforce's brand system, as the supporting colour. Seen in: Calm (https://brandsweets.com/colors/brands/calm-com), Salesforce (https://brandsweets.com/colors/brands/salesforce-com), Netlify (https://brandsweets.com/colors/brands/netlify-com), Opensea (https://brandsweets.com/colors/brands/opensea-io). — https://brandsweets.com/colors/lightskyblue

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

- On white (#ffffff): 3.01:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #277fa5 (4.5:1); AA: background → #2e2e2e (4.52:1); AAA: text → #1d5f7c (7.05:1)
- On black (#000000): 6.99:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #35a1d0 (7.16:1)

## Fonts for this mood

- technical: https://brandsweets.com/fonts/mood/technical
- 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/309fcf-9cb3c4-df4e69-1f232d-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: "#309fcf" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.