# #1f3bb7

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

## Values

- Hex: `#1f3bb7`
- RGB: rgb(31, 59, 183)
- HSL: hsl(229, 71%, 42%)
- OKLCH: oklch(0.423 0.197 266.8)
- Relative luminance: 0.0684
- Nearest named color: Cobalt Blue (#0047ab, Δ 3.405) — https://brandsweets.com/colors/cobalt
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/1f3bb7

## Tints & shades

- Tints (toward white): #2343d1, #3251dc, #4c67e1, #627ae4, #7c90e9, #96a6ed, #acb9f1, #c6cff5, #dce1f9, #f6f8fe
- Shades (toward black): #1c35a6, #193094, #172c87, #142676, #112064, #0e1b53, #0b1541, #091134, #060b23, #030611

## Harmonies

- Complementary: #b79b1f
- Analogous: #1f87b7, #4f1fb7
- Triadic: #b71f3b, #3bb71f
- Split-complementary: #b74f1f, #87b71f
- Tetradic: #b71f87, #b79b1f, #1fb74f

## Colors that go with #1f3bb7

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 #1f3bb7: softer than #000 and cool enough to feel like part of the same palette. Seen in: UEFA (https://brandsweets.com/colors/brands/uefa-com), HP (https://brandsweets.com/colors/brands/hp-com), Campus (https://brandsweets.com/palettes/friendly#campus), Hasbro (https://brandsweets.com/colors/brands/hasbro-com). — https://brandsweets.com/colors/charcoal
- **Sea Green** #2e8b57 [harmony, pool: triadic] — Sea Green completes a triad with #1f3bb7 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Intel (https://brandsweets.com/colors/brands/intel-com), Jack Daniel's (https://brandsweets.com/colors/brands/jackdaniels-com), Netflix (https://brandsweets.com/colors/brands/netflix), Paramount+ (https://brandsweets.com/colors/brands/paramountplus-com). — https://brandsweets.com/colors/seagreen
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #1f3bb7's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Glacier (https://brandsweets.com/palettes/cool#glacier), American Express (https://brandsweets.com/colors/brands/americanexpress-com). — https://brandsweets.com/colors/steelblue
- **Amber** #ffbf00 [pool] — Amber is paired with #1f3bb7 in 5 real palettes, including Walmart's brand system and Warner Bros.'s brand system, as the accent. Seen in: Walmart (https://brandsweets.com/colors/brands/walmart-com), Warner Bros. (https://brandsweets.com/colors/brands/warnerbros-com), Binance (https://brandsweets.com/colors/brands/binance-com), Wikipedia (https://brandsweets.com/colors/brands/wikipedia-org). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 5 real palettes, including Procter & Gamble's brand system and Zillow's brand system put Blue beside #1f3bb7, as the supporting colour. Seen in: Procter & Gamble (https://brandsweets.com/colors/brands/pg-com), Zillow (https://brandsweets.com/colors/brands/zillow-com), CVS (https://brandsweets.com/colors/brands/cvs-com), Tesco (https://brandsweets.com/colors/brands/tesco-com). — https://brandsweets.com/colors/blue
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #1f3bb7: 8 real palettes, including Blue Mono and Gopro's brand system, as the supporting colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Gopro (https://brandsweets.com/colors/brands/gopro-com), Qualcomm (https://brandsweets.com/colors/brands/qualcomm-com), Coca-Cola (https://brandsweets.com/colors/brands/coca-cola-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #1f3bb7 in 11 real palettes, including Behance's brand system and Walgreens's brand system, as the accent. Seen in: Behance (https://brandsweets.com/colors/brands/behance-net), Walgreens (https://brandsweets.com/colors/brands/walgreens-com), Chase (https://brandsweets.com/colors/brands/chase-com), Costco (https://brandsweets.com/colors/brands/costco-com). — https://brandsweets.com/colors/crimson
- **Dodger Blue** #1e90ff [pool] — Designers have shipped Dodger Blue with #1f3bb7: 7 real palettes, including Coursera's brand system and Absolut's brand system, as the supporting colour. Seen in: Coursera (https://brandsweets.com/colors/brands/coursera-org), Absolut (https://brandsweets.com/colors/brands/absolut-com), Cargo (https://brandsweets.com/colors/brands/cargo-site), Readymag (https://brandsweets.com/colors/brands/readymag-com). — https://brandsweets.com/colors/dodgerblue

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

- On white (#ffffff): 8.87:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.37:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #516be1 (4.54:1); AA: background → #bababa (4.57:1); AAA: text → #7c90e9 (7.02:1); AAA: background → #e6e6e6 (7.11:1)

## Brands using this color

- **NHL** — accent #0042bb (Δ 1.983) — https://brandsweets.com/colors/brands/nhl-com

## Curated palettes containing it

- **Ink & Paper** (minimal, editorial, clean) — #1b1b1b, #6e6e6e, #1e40af, #fcfbf7 — Two greys and one ink-blue link color: the palette of a well-set book page. — tool: https://brandsweets.com/palettes/new/1b1b1b-6e6e6e-1e40af-fcfbf7 — collection: https://brandsweets.com/palettes/minimal
- **Cobalt Pop** (bold, cool, vivid, modern) — #1e40af, #111827, #fb7185, #ffffff — One deep cobalt and one hot pink on white — a two-accent system for launches and campaign pages that need punch. — tool: https://brandsweets.com/palettes/new/1e40af-111827-fb7185-ffffff — collection: https://brandsweets.com/palettes/bold
- **Blue Mono** (monochrome, cool, clean, technical) — #1e40af, #60a5fa, #bfdbfe, #f8fafc, #172554 — One blue at four lightnesses — monochromatic in the colour-theory sense; the deep step is the text, the pale step the surface tint. — tool: https://brandsweets.com/palettes/new/1e40af-60a5fa-bfdbfe-f8fafc-172554 — collection: https://brandsweets.com/palettes/monochrome

## 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/1f3bb7-9c9fc4-df7e4e-231f2d-e9eef1?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: "#1f3bb7" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.