# #428bb8

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

## Values

- Hex: `#428bb8`
- RGB: rgb(66, 139, 184)
- HSL: hsl(203, 47%, 49%)
- OKLCH: oklch(0.609 0.1 238.5)
- Relative luminance: 0.2308
- Nearest named color: steelblue (#4682b4, Δ 2.487) — https://brandsweets.com/colors/steelblue
- Moods: cool, modern
- Page: https://brandsweets.com/colors/428bb8

## Tints & shades

- Tints (toward white): #5397c1, #65a2c8, #78adce, #8bb9d5, #9ec4dc, #adcde1, #bfd8e8, #d2e4ef, #e5eff6, #f8fafc
- Shades (toward black): #3d7fa9, #367196, #316687, #2a5874, #244c65, #1e3e52, #183343, #122531, #0c1922, #050b0f

## Harmonies

- Complementary: #b86f42
- Analogous: #42b8aa, #4250b8
- Triadic: #b8428b, #8bb842
- Split-complementary: #b84250, #b8aa42
- Tetradic: #aa42b8, #b86f42, #50b842

## Colors that go with #428bb8

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 #428bb8: softer than #000 and cool enough to feel like part of the same palette. Seen in: Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Auth0 (https://brandsweets.com/colors/brands/auth0-com), Dusty Blue (https://brandsweets.com/palettes/cool#dusty-blue), Plaid (https://brandsweets.com/colors/brands/plaid-com). — https://brandsweets.com/colors/charcoal
- **Copper** #b87333 [harmony, pool: complementary] — Copper sits directly opposite #428bb8 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), Dusk (https://brandsweets.com/palettes/cool#dusk), Atelier (https://brandsweets.com/palettes/elegant#atelier), Riverbed (https://brandsweets.com/palettes/muted#riverbed). — https://brandsweets.com/colors/copper
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #428bb8's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Slate Workspace (https://brandsweets.com/palettes/minimal#slate-workspace), Confluent (https://brandsweets.com/colors/brands/confluent-io), Elastic (https://brandsweets.com/colors/brands/elastic-co), HashiCorp (https://brandsweets.com/colors/brands/hashicorp-com). — https://brandsweets.com/colors/royalblue
- **Amber** #ffbf00 [pool] — Amber is paired with #428bb8 in 8 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), Google (https://brandsweets.com/colors/brands/google-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 4 real palettes, including Qualcomm's brand system and Readymag's brand system put Blue beside #428bb8, as the accent. Seen in: Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), Unity (https://brandsweets.com/colors/brands/unity-com), Activision (https://brandsweets.com/colors/brands/activision-com). — https://brandsweets.com/colors/blue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #428bb8: 7 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), General Mills (https://brandsweets.com/colors/brands/generalmills-com), Intel (https://brandsweets.com/colors/brands/intel-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #428bb8 in 10 real palettes, including Retro Pop and NASCAR's brand system, as the lead colour. Seen in: Retro Pop (https://brandsweets.com/palettes/playful#retro-pop), NASCAR (https://brandsweets.com/colors/brands/nascar-com), Wendy's (https://brandsweets.com/colors/brands/wendys-com), Redfin (https://brandsweets.com/colors/brands/redfin-com). — https://brandsweets.com/colors/crimson
- **Deep Sky Blue** #00bfff [pool] — Designers have shipped Deep Sky Blue with #428bb8: 8 real palettes, including Telegram's brand system and Astro's brand system, as the lead colour. Seen in: Telegram (https://brandsweets.com/colors/brands/telegram-org), Astro (https://brandsweets.com/colors/brands/astro-build), Deep Water (https://brandsweets.com/palettes/dark#deep-water), Patreon (https://brandsweets.com/colors/brands/patreon-com). — https://brandsweets.com/colors/deepskyblue

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

- On white (#ffffff): 3.74:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #3b7da5 (4.5:1); AA: background → #1c1c1c (4.56:1); AAA: text → #2d5d7c (7.07:1)
- On black (#000000): 5.62:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #5e9dc5 (7.1:1)

## 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/428bb8-9cb0c4-df4e5d-1f222d-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: "#428bb8" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.