Color
#3f4e69
#3f4e69rgb(63, 78, 105)hsl(219, 25%, 33%)oklch(0.423 0.049 261.9)Colors that go with #3f4e69
Sienna, Cadet Blue and Champagne lead the list. Each partner is a real named colour with the reason it works — a wheel relationship, a neutral that carries it, or a pairing lifted from a palette or brand system that actually shipped — and every pair opens in the palette tool.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #3f4e69 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #3f4e69: 4 real palettes, including Dusk and Open House, as the supporting colour.
Champagne #f7e7ce
shipped4 real palettes, including Darkroom and Sweetgreen's brand system put Champagne beside #3f4e69, as the surface under it.
Copper #b87333
shippedDesigners have shipped Copper with #3f4e69: 4 real palettes, including Desert Road and Dusk, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #3f4e69 in 6 real palettes, including Codecademy's brand system and Marvel's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #3f4e69: 9 real palettes, including HP's brand system and Hinge's brand system, as the accent.
Goldenrod #daa520
shippedGoldenrod shows up next to #3f4e69 in 4 real palettes, including Fireside and Open House, as the accent.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #3f4e69: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #3f4e69
Tints & shades
Harmonies
Contrast
| #3f4e69 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 8.38:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.51:1 | fail | fail | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f4e69 as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Point any MCP client at the shared colors endpoint and your agent gets the same engine as this page — direct_palette, edit_direction, check_palette, check_contrast — read-only, no key. Every direction it proposes comes with a /colors/d/… link: open it, lock what you like, paste the link back, and the agent edits rather than re-rolls.
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
›analyze #3f4e69 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f4e69-9ca5c4-df664e-211f2d-e9f0f1?lock=0&style=vibrantWant the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.
Machine-readable: color.md