# #307fd5

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

## Values

- Hex: `#307fd5`
- RGB: rgb(48, 127, 213)
- HSL: hsl(211, 66%, 51%)
- OKLCH: oklch(0.592 0.152 253.4)
- Relative luminance: 0.2061
- Nearest named color: Haddock’s Sweater (#277aba, Δ 4.327) — https://brandsweets.com/colors/haddocks-sweater
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/307fd5

## Tints & shades

- Tints (toward white): #458cd9, #5697dc, #6ba4e1, #80b1e5, #95bee9, #a6c8ed, #bbd5f1, #d0e2f5, #e1edf9, #f7fafd
- Shades (toward black): #2873c3, #2469b2, #205c9d, #1c5087, #184677, #143961, #102d4c, #0b2037, #081626, #030a11

## Harmonies

- Complementary: #d58530
- Analogous: #30d2d5, #3230d5
- Triadic: #d5307f, #7fd530
- Split-complementary: #d53230, #d2d530
- Tetradic: #d530d2, #d58530, #30d532

## Colors that go with #307fd5

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 #307fd5: softer than #000 and cool enough to feel like part of the same palette. Seen in: Disney (https://brandsweets.com/colors/brands/disney-com), 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). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [harmony, pool: triadic] — Crimson completes a triad with #307fd5 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: NASCAR (https://brandsweets.com/colors/brands/nascar-com), Pizza Hut (https://brandsweets.com/colors/brands/pizzahut-com), State Farm (https://brandsweets.com/colors/brands/statefarm-com), Foot Locker (https://brandsweets.com/colors/brands/footlocker-com). — https://brandsweets.com/colors/crimson
- **Copper** #b87333 [harmony, pool: complementary] — Copper sits directly opposite #307fd5 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). — https://brandsweets.com/colors/copper
- **Amber** #ffbf00 [pool] — Amber is paired with #307fd5 in 12 real palettes, including Wired's brand system and Walmart's brand system, as the accent. Seen in: Wired (https://brandsweets.com/colors/brands/wired-com), Walmart (https://brandsweets.com/colors/brands/walmart-com), Google (https://brandsweets.com/colors/brands/google-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 14 real palettes, including Readymag's brand system and Qualcomm's brand system put Blue beside #307fd5, as the supporting colour. Seen in: Readymag (https://brandsweets.com/colors/brands/readymag-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), BBC (https://brandsweets.com/colors/brands/bbc-com), EA (https://brandsweets.com/colors/brands/ea-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #307fd5: 11 real palettes, including Hershey's's brand system and General Mills's brand system, as the supporting colour. Seen in: Hershey's (https://brandsweets.com/colors/brands/hersheys-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com), Intel (https://brandsweets.com/colors/brands/intel-com), Carrefour (https://brandsweets.com/colors/brands/carrefour-com). — https://brandsweets.com/colors/cobalt
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #307fd5: 9 real palettes, including Astro's brand system and Telegram's brand system, as the supporting colour. Seen in: Astro (https://brandsweets.com/colors/brands/astro-build), Telegram (https://brandsweets.com/colors/brands/telegram-org), Patreon (https://brandsweets.com/colors/brands/patreon-com), Deep Water (https://brandsweets.com/palettes/dark#deep-water). — https://brandsweets.com/colors/deepskyblue
- **Firebrick** #b22222 [pool] — Designers have shipped Firebrick with #307fd5: 6 real palettes, including Honda's brand system and AT&T's brand system, as the supporting colour. Seen in: Honda (https://brandsweets.com/colors/brands/honda-com), AT&T (https://brandsweets.com/colors/brands/att-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Campbell's (https://brandsweets.com/colors/brands/campbells-com). — https://brandsweets.com/colors/firebrick

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

- On white (#ffffff): 4.1:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #2a78cb (4.52:1); AA: background → #121212 (4.57:1); AAA: text → #1f5a98 (7.06:1)
- On black (#000000): 5.12:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #5a99dd (7.04:1)

## Brands using this color

- **Substack** — secondary #0083d5 (Δ 1.772) — https://brandsweets.com/colors/brands/substack-com

## 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/307fd5-9cabc4-df534e-1f202d-e9f1f1?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: "#307fd5" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.