Arctic
Open in tool →Navy type on white with an ice-blue accent: crisp and corporate without going grey.
Color
#181b2f
#181b2f
hex
#181b2frgb
rgb(24, 27, 47)hsl
hsl(232, 32%, 14%)oklch
oklch(0.23 0.039 276.4)Closest name: Dark Knight (#151931)Relative luminance 0.0118
Colors that go with #181b2f
Charcoal, Dark Olive Green and Sea Green 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 #181b2f: softer than #000 and cool enough to feel like part of the same palette.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #181b2f on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #181b2f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Sienna #a0522d
split-complementshippedSienna is a split-complement of #181b2f: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Slate Blue #6a5acd
analogousshippedSlate Blue is #181b2f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Steel Blue #4682b4
analogousshippedSteel Blue is #181b2f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Amber #ffbf00
shippedAmber is paired with #181b2f in 18 real palettes, including Blueprint and Southwest Airlines's brand system, as the accent.
Blue #0000ff
shipped23 real palettes, including Warp's brand system and Monzo's brand system put Blue beside #181b2f, as the supporting colour.
Real palettes that use #181b2f
Tints & shades
Harmonies
Contrast
| #181b2f as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 16.98:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.24:1 | 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 #181b2f as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#181b2f reads as cool, muted, dark. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #181b2f
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 #181b2f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/181b2f-9c9dc4-df864e-231f2d-e9eef1?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