Color
#3d5571
#3d5571rgb(61, 85, 113)hsl(212, 30%, 34%)oklch(0.442 0.055 252.8)Colors that go with #3d5571
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 #3d5571 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped5 real palettes, including Alaska Airlines's brand system and Tesco's brand system put Blue beside #3d5571, as the accent.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #3d5571: 4 real palettes, including Dusk and Open House, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3d5571 in 11 real palettes, including Codecademy's brand system and Pepsi's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #3d5571: 17 real palettes, including HP's brand system and Hinge's brand system, as the accent.
Goldenrod #daa520
shippedGoldenrod shows up next to #3d5571 in 5 real palettes, including Open House and Fireside, as the accent.
Medium Sea Green #3cb371
shippedMedium Sea Green is paired with #3d5571 in 5 real palettes, including Console Light and Mint Modern, as the accent.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #3d5571: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #3d5571
Tints & shades
Harmonies
Contrast
| #3d5571 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.67:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.74:1 | 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 #3d5571 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 #3d5571 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3d5571-9caac4-df564e-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