# #631fa3

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

## Values

- Hex: `#631fa3`
- RGB: rgb(99, 31, 163)
- HSL: hsl(271, 68%, 38%)
- OKLCH: oklch(0.422 0.194 301.5)
- Relative luminance: 0.0628
- Nearest named color: rebeccapurple (#663399, Δ 3.85) — https://brandsweets.com/colors/rebeccapurple
- Moods: cool, vivid, technical, modern
- Page: https://brandsweets.com/colors/631fa3

## Tints & shades

- Tints (toward white): #7324bc, #8229d6, #9143db, #a05ce0, #af76e5, #be90ea, #cda9ef, #dcc3f4, #ebddf8, #faf6fd
- Shades (toward black): #5b1d96, #511985, #491778, #3f1467, #37115a, #2f0f4d, #250b3c, #1d092f, #12061e, #0a0311

## Harmonies

- Complementary: #5fa31f
- Analogous: #211fa3, #a31fa1
- Triadic: #a3631f, #1fa363
- Split-complementary: #a1a31f, #1fa321
- Tetradic: #a3211f, #5fa31f, #1fa1a3

## Colors that go with #631fa3

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 #631fa3 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 #631fa3: 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), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/charcoal
- **Crimson** #dc143c [pool] — Crimson is paired with #631fa3 in 3 real palettes, including Wells Fargo's brand system and Gemstone, as the lead colour. Seen in: Wells Fargo (https://brandsweets.com/colors/brands/wellsfargo-com), Gemstone (https://brandsweets.com/palettes/vivid#gemstone), Lenovo (https://brandsweets.com/colors/brands/lenovo-com). — https://brandsweets.com/colors/crimson
- **Denim** #1560bd [pool] — Designers have shipped Denim with #631fa3: 3 real palettes, including Slack's brand system and Linkedin's brand system, as the lead colour. Seen in: Slack (https://brandsweets.com/colors/brands/slack-com), Linkedin (https://brandsweets.com/colors/brands/linkedin-com), Hinge (https://brandsweets.com/colors/brands/hinge-co). — https://brandsweets.com/colors/denim
- **Tomato** #ff6347 [pool] — 3 real palettes, including FedEx's brand system and dbt Labs's brand system put Tomato beside #631fa3, 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 #631fa3 — 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 #631fa3: 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 #631fa3'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

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

- On white (#ffffff): 9.31:1 — AA pass, AA-large pass, AAA pass
- On black (#000000): 2.26:1 — AA fail, AA-large fail, AAA fail. Fix: AA: text → #994fde (4.53:1); AA: background → #b5b5b5 (4.54:1); AAA: text → #b47ee7 (7.08:1); AAA: background → #e0e0e0 (7.05:1)

## 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/631fa3-b59cc4-c7cb62-2c1f2d-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: "#631fa3" })`), `check_contrast` (with fixes), `generate_palette` (explore around locks), `suggest_palette` (mood/industry → curated-first), `list_palettes`.