# #231d63

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

## Values

- Hex: `#231d63`
- RGB: rgb(35, 29, 99)
- HSL: hsl(245, 55%, 25%)
- OKLCH: oklch(0.288 0.118 279.8)
- Relative luminance: 0.0214
- Nearest named color: midnightblue (#191970, Δ 2.991) — https://brandsweets.com/colors/midnightblue
- Moods: cool, dark, luxury, bold, modern
- Page: https://brandsweets.com/colors/231d63

## Tints & shades

- Tints (toward white): #2c257e, #372e9e, #4136ba, #5449ca, #7269d3, #8c84db, #a6a0e3, #c0bceb, #dedbf5, #f8f7fd
- Shades (toward black): #201a5b, #1d1853, #1a164b, #171443, #15113b, #110e2f, #0e0b28, #0b0920, #080718, #060510

## Harmonies

- Complementary: #5d631d
- Analogous: #1d3a63, #461d63
- Triadic: #63231d, #1d6323
- Split-complementary: #63461d, #3a631d
- Tetradic: #631d3a, #5d631d, #1d6346

## Colors that go with #231d63

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 #231d63: softer than #000 and cool enough to feel like part of the same palette. Seen in: CeraVe (https://brandsweets.com/colors/brands/cerave-com), Plaid (https://brandsweets.com/colors/brands/plaid-com), Microsoft (https://brandsweets.com/colors/brands/microsoft-com), Boeing (https://brandsweets.com/colors/brands/boeing-com). — https://brandsweets.com/colors/charcoal
- **Steel Blue** #4682b4 [harmony, pool: analogous] — Steel Blue is #231d63's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Plaid (https://brandsweets.com/colors/brands/plaid-com), Discover (https://brandsweets.com/colors/brands/discover-com), Deep Water (https://brandsweets.com/palettes/dark#deep-water), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/steelblue
- **Amber** #ffbf00 [pool] — Amber is paired with #231d63 in 4 real palettes, including Southwest Airlines's brand system and Beach Hut, as the accent. Seen in: Southwest Airlines (https://brandsweets.com/colors/brands/southwest-com), Beach Hut (https://brandsweets.com/palettes/light#beach-hut), Blueprint (https://brandsweets.com/palettes/technical#blueprint), McDonald's (https://brandsweets.com/colors/brands/mcdonalds-com). — https://brandsweets.com/colors/amber
- **Blue** #0000ff [pool] — 5 real palettes, including Sketch's brand system and Monzo's brand system put Blue beside #231d63, as the accent. Seen in: Sketch (https://brandsweets.com/colors/brands/sketch-com), Monzo (https://brandsweets.com/colors/brands/monzo-com), Penpot (https://brandsweets.com/colors/brands/penpot-app), Alaska Airlines (https://brandsweets.com/colors/brands/alaskaair-com). — https://brandsweets.com/colors/blue
- **Cadet Blue** #5f9ea0 [pool] — Designers have shipped Cadet Blue with #231d63: 6 real palettes, including SoFi's brand system and Open House, as the supporting colour. Seen in: SoFi (https://brandsweets.com/colors/brands/sofi-com), Open House (https://brandsweets.com/palettes/clean#open-house), Coastal (https://brandsweets.com/palettes/cool#coastal), Dusk (https://brandsweets.com/palettes/cool#dusk). — https://brandsweets.com/colors/cadetblue
- **Cobalt Blue** #0047ab [pool] — Designers have shipped Cobalt Blue with #231d63: 8 real palettes, including Blue Mono and Purina Pro Plan's brand system, as the lead colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Purina Pro Plan (https://brandsweets.com/colors/brands/chewy-com), MLB (https://brandsweets.com/colors/brands/mlb-com), Glacier (https://brandsweets.com/palettes/cool#glacier). — https://brandsweets.com/colors/cobalt
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #231d63: 5 real palettes, including Blue Mono and Peacock's brand system, as the supporting colour. Seen in: Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Peacock (https://brandsweets.com/colors/brands/peacocktv-com), Arctic (https://brandsweets.com/palettes/clean#arctic), Blizzard (https://brandsweets.com/colors/brands/blizzard-com). — https://brandsweets.com/colors/cornflowerblue
- **Crimson** #dc143c [pool] — Crimson is paired with #231d63 in 9 real palettes, including Nintendo's brand system and Casper Sleep's brand system, as the supporting colour. Seen in: Nintendo (https://brandsweets.com/colors/brands/nintendo-com), Casper Sleep (https://brandsweets.com/colors/brands/casper-com), Marvel (https://brandsweets.com/colors/brands/marvel-com), Frost & Ember (https://brandsweets.com/palettes/bold#frost-and-ember). — https://brandsweets.com/colors/crimson

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

- On white (#ffffff): 14.71:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.43:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #7269d3 (4.68:1); AA: background → #8f8f8f (4.55:1); AAA: text → #938cde (7.05:1); AAA: background → #b3b3b3 (7.02:1)

## 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/231d63-a49cc4-dfa54e-261f2d-e9ecf1?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: "#231d63" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.