Darkroom
Open in tool →Sepia, faded ochre and a teal shadow on aged paper — the photograph-in-a-drawer palette, tuned so it still passes AA.
Color
#3f585f
#3f585f
hex
#3f585frgb
rgb(63, 88, 95)hsl
hsl(193, 20%, 31%)oklch
oklch(0.443 0.032 216.9)Closest name: Arctic Nights (#345c61)Relative luminance 0.0886
Colors that go with #3f585f
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 #3f585f on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped7 real palettes, including Jeep's brand system and Rolex's brand system put Blue beside #3f585f, as the accent.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #3f585f: 4 real palettes, including Dusk and Paper & Pine, as the supporting colour.
Copper #b87333
shippedDesigners have shipped Copper with #3f585f: 4 real palettes, including Desert Road and Dusk, as the lead colour.
Crimson #dc143c
shippedCrimson is paired with #3f585f in 5 real palettes, including Codecademy's brand system and Gemstone, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #3f585f: 9 real palettes, including HP's brand system and Hinge's brand system, as the accent.
Goldenrod #daa520
shippedGoldenrod shows up next to #3f585f in 5 real palettes, including Fireside and Mid-Century, as the accent.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #3f585f: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #3f585f
Tints & shades
Harmonies
Contrast
| #3f585f as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.57:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.77:1 | 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 #3f585f as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Palettes built around it
mcpConnect your agent — build around #3f585f
live endpointPoint 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.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #3f585f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/3f585f-a2b5be-df4e75-1f242d-e9f1ef?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