Color
#3f5e78
#3f5e78rgb(63, 94, 120)hsl(207, 31%, 36%)oklch(0.469 0.056 244.7)Colors that go with #3f5e78
Sienna, Blue and Cadet Blue 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 #3f5e78 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped8 real palettes, including Tesco's brand system and Activision's brand system put Blue beside #3f5e78, as the supporting colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #3f5e78: 4 real palettes, including Dusk and Open House, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3f5e78: 4 real palettes, including Fintech Trust and Ink & Paper, as the lead colour.
Copper #b87333
shippedDesigners have shipped Copper with #3f5e78: 4 real palettes, including Dusk and Desert Road, as the accent.
Crimson #dc143c
shippedCrimson is paired with #3f5e78 in 14 real palettes, including Codecademy's brand system and Gemstone, as the accent.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #3f5e78: 4 real palettes, including Lamborghini's brand system and Venmo's brand system, as the supporting colour.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #3f5e78: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #3f5e78
Tints & shades
Harmonies
Contrast
| #3f5e78 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 6.81:1 | pass | pass | fail |
|
Aaon black | 3.08:1 | fail | pass | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3f5e78 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 #3f5e78 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f5e78-9cadc4-df4e53-1f212d-e9f1f1?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