# #661bb1

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

## Values

- Hex: `#661bb1`
- RGB: rgb(102, 27, 177)
- HSL: hsl(270, 74%, 40%)
- OKLCH: oklch(0.435 0.211 299.5)
- Relative luminance: 0.0678
- Nearest named color: Fuchsia Nebula (#7722aa, Δ 3.99) — https://brandsweets.com/colors/fuchsia-nebula
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/661bb1

## Tints & shades

- Tints (toward white): #751ecc, #852adf, #9140e2, #a15be6, #b075ea, #bf90ee, #cfabf2, #dbc1f6, #ebdcfa, #faf6fe
- Shades (toward black): #5c18a0, #541692, #4a1381, #421173, #380f62, #2e0c50, #260a43, #1c0731, #140523, #0a0312

## Harmonies

- Complementary: #66b11b
- Analogous: #1b1bb1, #b11bb1
- Triadic: #b1661b, #1bb166
- Split-complementary: #b1b11b, #1bb11b
- Tetradic: #b11b1b, #66b11b, #1bb1b1

## Colors that go with #661bb1

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

- **Olive Green** #808000 [harmony: complementary] — Olive Green sits directly opposite #661bb1 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
- **Charcoal** #36454f [role, pool] — Charcoal is the text near-black for #661bb1: 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
- **Tomato** #ff6347 [pool] — 3 real palettes, including FedEx's brand system and dbt Labs's brand system put Tomato beside #661bb1, as the supporting colour. Seen in: FedEx (https://brandsweets.com/colors/brands/fedex-com), dbt Labs (https://brandsweets.com/colors/brands/getdbt-com), GitLab (https://brandsweets.com/colors/brands/gitlab). — https://brandsweets.com/colors/tomato
- **Teal** #008080 [harmony, pool: triadic] — Teal completes a triad with #661bb1 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash. Seen in: Gemstone (https://brandsweets.com/palettes/vivid#gemstone). — https://brandsweets.com/colors/teal
- **Sea Green** #2e8b57 [harmony: split] — Sea Green is a split-complement of #661bb1: nearly opposite, so it still pops against it, without the vibrating edge of a true complement. — https://brandsweets.com/colors/seagreen
- **Royal Blue** #4169e1 [harmony, pool: analogous] — Royal Blue is #661bb1'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). — https://brandsweets.com/colors/royalblue
- **Blue Violet** #8a2be2 [pool] — Blue Violet is paired with #661bb1 in two real palettes: Twitch's brand system and Taco Bell's brand system, as the lead colour. Seen in: Twitch (https://brandsweets.com/colors/brands/twitch-tv), Taco Bell (https://brandsweets.com/colors/brands/tacobell-com). — https://brandsweets.com/colors/blueviolet
- **Cornflower Blue** #6495ed [pool] — Designers have shipped Cornflower Blue with #661bb1: two real palettes: Peacock's brand system and Blue Mono, as the accent. Seen in: Peacock (https://brandsweets.com/colors/brands/peacocktv-com), Blue Mono (https://brandsweets.com/palettes/cool#blue-mono). — https://brandsweets.com/colors/cornflowerblue

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

- On white (#ffffff): 8.91:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.36:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #994ee4 (4.56:1); AA: background → #bababa (4.59:1); AAA: text → #b57eec (7.16:1); AAA: background → #e6e6e6 (7.14:1)

## 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/661bb1-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: "#661bb1" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.