# #540b9d

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

## Values

- Hex: `#540b9d`
- RGB: rgb(84, 11, 157)
- HSL: hsl(270, 87%, 33%)
- OKLCH: oklch(0.384 0.2 297.3)
- Relative luminance: 0.0456
- Nearest named color: Intergalactic Settlement (#5b1e8b, Δ 4.007) — https://brandsweets.com/colors/intergalactic-settlement
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/540b9d

## Tints & shades

- Tints (toward white): #660dbf, #750fdb, #871fef, #963bf1, #a85df4, #b879f6, #c99bf8, #d9b7fa, #ebd9fc, #faf5fe
- Shades (toward black): #4d0a8f, #450981, #3d0872, #360764, #30065b, #29054c, #21043e, #1a0330, #120221, #0a0113

## Harmonies

- Complementary: #549d0b
- Analogous: #0b0b9d, #9d0b9d
- Triadic: #9d540b, #0b9d54
- Split-complementary: #9d9d0b, #0b9d0b
- Tetradic: #9d0b0b, #549d0b, #0b9d9d

## Colors that go with #540b9d

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

- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #540b9d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces. Seen in: Wayfair (https://brandsweets.com/colors/brands/wayfair-com), Discord (https://brandsweets.com/colors/brands/discord), Nivea (https://brandsweets.com/colors/brands/nivea-com). — https://brandsweets.com/colors/royalblue
- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #540b9d 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/olive
- **Midnight Blue** #191970 [pool] — 3 real palettes, including Kraken's brand system and Blue Mono put Midnight Blue beside #540b9d, as the lead colour. Seen in: Kraken (https://brandsweets.com/colors/brands/kraken-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust). — https://brandsweets.com/colors/midnightblue
- **Steel Blue** #4682b4 [pool] — Designers have shipped Steel Blue with #540b9d: 3 real palettes, including FedEx's brand system and Hershey's's brand system, as the accent. Seen in: FedEx (https://brandsweets.com/colors/brands/fedex-com), Hershey's (https://brandsweets.com/colors/brands/hersheys-com), Fintech Trust (https://brandsweets.com/palettes/cool#fintech-trust). — https://brandsweets.com/colors/steelblue
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #540b9d — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Sapphire & Gold (https://brandsweets.com/palettes/luxury#sapphire-and-gold), Gemstone (https://brandsweets.com/palettes/vivid#gemstone). — https://brandsweets.com/colors/teal
- **Forest Green** #228b22 [harmony: split] — Forest Green is a split-complement of #540b9d: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. — https://brandsweets.com/colors/forestgreen
- **Blue Violet** #8a2be2 [pool] — Blue Violet is paired with #540b9d in two real palettes: Taco Bell's brand system and Twitch's brand system, as the supporting colour. Seen in: Taco Bell (https://brandsweets.com/colors/brands/tacobell-com), Twitch (https://brandsweets.com/colors/brands/twitch-tv). — https://brandsweets.com/colors/blueviolet
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #540b9d: softer than #000 and cool enough to feel like part of the same palette. Seen in: dbt Labs (https://brandsweets.com/colors/brands/getdbt-com). — https://brandsweets.com/colors/charcoal

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

- On white (#ffffff): 10.99:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 1.91:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #9c45f2 (4.55:1); AA: background → #a6a6a6 (4.51:1); AAA: text → #b879f6 (7.1:1); AAA: background → #cfcfcf (7.05:1)

## Brands using this color

- **Taco Bell** — primary #501098 (Δ 1.119) — https://brandsweets.com/colors/brands/tacobell-com

## 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/540b9d-b59cc4-c9cb62-2c1f2d-eae9f1?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: "#540b9d" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.