# #3991ea

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

## Values

- Hex: `#3991ea`
- RGB: rgb(57, 145, 234)
- HSL: hsl(210, 81%, 57%)
- OKLCH: oklch(0.647 0.157 251.8)
- Relative luminance: 0.2706
- Nearest named color: Fresh Blue of Bel Air (#069af3, Δ 2.71) — https://brandsweets.com/colors/fresh-blue-of-bel-air
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/3991ea

## Tints & shades

- Tints (toward white): #4b9cec, #5da6ee, #70b0f0, #82baf2, #99c7f4, #acd1f6, #bedbf8, #d1e6fa, #e3f0fc, #f6fafe
- Shades (toward black): #2185e8, #1675d4, #1469bd, #115ca6, #0f4f8f, #0c4073, #0a335c, #072645, #04172a, #020a12

## Harmonies

- Complementary: #ea9139
- Analogous: #39eaea, #3939ea
- Triadic: #ea3991, #91ea39
- Split-complementary: #ea3939, #eaea39
- Tetradic: #ea39ea, #ea9139, #39ea39

## Colors that go with #3991ea

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 #3991ea: softer than #000 and cool enough to feel like part of the same palette. Seen in: Blizzard (https://brandsweets.com/colors/brands/blizzard-com), Lamborghini (https://brandsweets.com/colors/brands/lamborghini-com), Disney (https://brandsweets.com/colors/brands/disney-com), Lido (https://brandsweets.com/palettes/vivid#lido). — https://brandsweets.com/colors/charcoal
- **Amber** #ffbf00 [pool] — Amber is paired with #3991ea in 12 real palettes, including Heatwave and Google's brand system, as the supporting colour. Seen in: Heatwave (https://brandsweets.com/palettes/warm#heatwave), Google (https://brandsweets.com/colors/brands/google-com), Blueprint (https://brandsweets.com/palettes/technical#blueprint), NBA (https://brandsweets.com/colors/brands/nba-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 9 real palettes, including Unity's brand system and Readymag's brand system put Blue beside #3991ea, as the supporting colour. Seen in: Unity (https://brandsweets.com/colors/brands/unity-com), Readymag (https://brandsweets.com/colors/brands/readymag-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Cargo (https://brandsweets.com/colors/brands/cargo-site). — https://brandsweets.com/colors/blue
- **Blue Violet** #8a2be2 [pool] — Blue Violet is paired with #3991ea in 4 real palettes, including Render's brand system and Yahoo's brand system, as the lead colour. Seen in: Render (https://brandsweets.com/colors/brands/render-com), Yahoo (https://brandsweets.com/colors/brands/yahoo-com), ClickUp (https://brandsweets.com/colors/brands/clickup-com), Circuit (https://brandsweets.com/palettes/technical#circuit). — https://brandsweets.com/colors/blueviolet
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #3991ea: 7 real palettes, including Blue Mono and Hershey's's brand system, as the lead colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Carrefour (https://brandsweets.com/colors/brands/carrefour-com), General Mills (https://brandsweets.com/colors/brands/generalmills-com). — https://brandsweets.com/colors/cobalt
- **Crimson** #dc143c [pool] — Crimson is paired with #3991ea in 6 real palettes, including NASCAR's brand system and Pizza Hut's brand system, as the supporting colour. Seen in: NASCAR (https://brandsweets.com/colors/brands/nascar-com), Pizza Hut (https://brandsweets.com/colors/brands/pizzahut-com), Foot Locker (https://brandsweets.com/colors/brands/footlocker-com), Behance (https://brandsweets.com/colors/brands/behance-net). — https://brandsweets.com/colors/crimson
- **Dark Orange** #ff8c00 [pool] — Dark Orange shows up next to #3991ea in 4 real palettes, including Playground and Elastic's brand system, as the lead colour. Seen in: Playground (https://brandsweets.com/palettes/bold#playground), Elastic (https://brandsweets.com/colors/brands/elastic-co), Learning App (https://brandsweets.com/palettes/playful#learning-app), Ahrefs (https://brandsweets.com/colors/brands/ahrefs-com). — https://brandsweets.com/colors/darkorange
- **Dark Goldenrod** #b8860b [harmony: complementary] — Dark Goldenrod sits directly opposite #3991ea on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. — https://brandsweets.com/colors/darkgoldenrod

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

- On white (#ffffff): 3.27:1 — AA fail, AA-large pass, AAA fail. Fix: AA: text → #1675d4 (4.64:1); AA: background → #262626 (4.62:1); AAA: text → #1159a2 (7.06:1)
- On black (#000000): 6.41:1 — AA pass, AA-large pass, AAA fail. Fix: AAA: text → #4699ec (7.03:1)

## 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/3991ea-9cabc4-df514e-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: "#3991ea" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.