# #243f5b

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

## Values

- Hex: `#243f5b`
- RGB: rgb(36, 63, 91)
- HSL: hsl(211, 43%, 25%)
- OKLCH: oklch(0.36 0.059 250.6)
- Relative luminance: 0.0469
- Nearest named color: Capital Blue (#1a4157, Δ 1.469) — https://brandsweets.com/colors/capital-blue
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/243f5b

## Tints & shades

- Tints (toward white): #2f5075, #3a6592, #4476ab, #5788bc, #749dc8, #8eafd2, #a7c1dc, #c1d3e6, #dee8f2, #f8fafc
- Shades (toward black): #213a54, #1f354d, #1c3045, #192b3e, #162637, #111e2c, #0f1924, #0c141d, #090f16, #060a0f

## Harmonies

- Complementary: #5b4124
- Analogous: #245a5b, #25245b
- Triadic: #5b243f, #3f5b24
- Split-complementary: #5b2524, #5a5b24
- Tetradic: #5b245a, #5b4124, #245b25

## Colors that go with #243f5b

Named partners (harmony on the OKLCH wheel, co-occurrence in curated palettes and brand systems, and the neutrals that carry it), best first:

- **Dark Olive Green** #556b2f [harmony, pool: split] — Dark Olive Green is a split-complement of #243f5b: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove), 7-Eleven (https://brandsweets.com/colors/brands/7-eleven-com), Oatmeal (https://brandsweets.com/palettes/neutral#oatmeal), Undergrowth (https://brandsweets.com/palettes/dark#undergrowth). — https://brandsweets.com/colors/darkolivegreen
- **Teal** #008080 [harmony, pool: analogous] — Teal is #243f5b's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Stanley (https://brandsweets.com/colors/brands/stanley1913-com), Gusto (https://brandsweets.com/colors/brands/gusto-com), N26 (https://brandsweets.com/colors/brands/n26-com), Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold). — https://brandsweets.com/colors/teal
- **Sienna** #a0522d [harmony, pool: complementary] — Sienna sits directly opposite #243f5b on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight. Seen in: Olive Grove (https://brandsweets.com/palettes/muted#olive-grove). — https://brandsweets.com/colors/sienna
- **Blue** #0000ff [pool] — 11 real palettes, including Alaska Airlines's brand system and Jeep's brand system put Blue beside #243f5b, as the accent. Seen in: Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com), Jeep (https://brandsweets.com/colors/brands/jeep-com), Minecraft (https://brandsweets.com/colors/brands/minecraft-net), Dunkin' (https://brandsweets.com/colors/brands/dunkindonuts-com). — https://brandsweets.com/colors/blue
- **Blush Pink** #e8b4b8 [pool] — 4 real palettes, including Garden Wedding and Rain Garden put Blush Pink beside #243f5b, as the supporting colour. Seen in: Garden Wedding (https://brandsweets.com/palettes/light#garden-wedding), Rain Garden (https://brandsweets.com/palettes/cool#rain-garden), Nursery (https://brandsweets.com/palettes/light#nursery), Blush (https://brandsweets.com/palettes/light#blush). — https://brandsweets.com/colors/blush-pink
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #243f5b: 6 real palettes, including Open House and Coastal, as the supporting colour. Seen in: Open House (https://brandsweets.com/palettes/clean#open-house), Coastal (https://brandsweets.com/palettes/cool#coastal), Paper & Pine (https://brandsweets.com/palettes/minimal#paper-and-pine), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty). — https://brandsweets.com/colors/cadetblue
- **Copper** #b87333 [pool] — Designers have shipped Copper with #243f5b: 7 real palettes, including Notion's brand system and Clean Beauty. Seen in: Notion (https://brandsweets.com/colors/brands/notion), Clean Beauty (https://brandsweets.com/palettes/minimal#clean-beauty), Dusk (https://brandsweets.com/palettes/cool#dusk), Bakery (https://brandsweets.com/palettes/warm#bakery). — https://brandsweets.com/colors/copper
- **White Smoke** #f5f5f5 [role] — White Smoke is the surface for #243f5b: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy. — https://brandsweets.com/colors/whitesmoke

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

- On white (#ffffff): 10.84:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.94:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #4679af (4.61:1); AA: background → #a8a8a8 (4.56:1); AAA: text → #719ac6 (7.14:1); AAA: background → #d1d1d1 (7.1:1)

## Brands using this color

- **Tumblr** — primary #304058 (Δ 1.675) — https://brandsweets.com/colors/brands/tumblr-com

## Fonts for this mood

- luxury: https://brandsweets.com/fonts/mood/luxury
- bold: https://brandsweets.com/fonts/mood/bold
- 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/243f5b-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: "#243f5b" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.