Color
#51657b
#51657brgb(81, 101, 123)hsl(211, 21%, 40%)oklch(0.499 0.043 251.1)Colors that go with #51657b
Charcoal, Sienna and Amber 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.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #51657b: softer than #000 and cool enough to feel like part of the same palette.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #51657b on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Amber #ffbf00
shippedAmber is paired with #51657b in 5 real palettes, including Lemon Squeezy's brand system and McDonald's's brand system, as the lead colour.
Blue #0000ff
shipped4 real palettes, including Activision's brand system and Warp's brand system put Blue beside #51657b, as the accent.
Champagne #f7e7ce
shipped5 real palettes, including Darkroom and BrandSweets's brand system put Champagne beside #51657b, as the surface under it.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #51657b: 5 real palettes, including Fintech Trust and Ink & Paper, as the lead colour.
Copper #b87333
shippedDesigners have shipped Copper with #51657b: 5 real palettes, including Dusk and Desert Road, as the accent.
Crimson #dc143c
shippedCrimson is paired with #51657b in 15 real palettes, including Retro Pop and Gemstone, as the lead colour.
Real palettes that use #51657b
Tints & shades
Harmonies
Contrast
| #51657b as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 6:1 | pass | pass | fail |
|
Aaon black | 3.5:1 | 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 #51657b as the background.
Brands using this color
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 #51657b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/51657b-9cabc4-df534e-1f202d-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