Color
#21030d
#21030drgb(33, 3, 13)hsl(340, 83%, 7%)oklch(0.168 0.056 2.2)Colors that go with #21030d
Charcoal, Rust 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 body-text near-black for #21030d: its slight blue cast keeps type crisp beside a warm colour where pure #000 looks heavy.
Rust #b7410e
analogousshippedRust is #21030d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Sea Green #2e8b57
split-complementshippedSea Green is a split-complement of #21030d: nearly opposite, so it still pops against it, without the vibrating edge of a true complement.
Steel Blue #4682b4
triadicshippedSteel Blue completes a triad with #21030d — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Teal #008080
complementaryshippedTeal sits directly opposite #21030d 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 #21030d in 14 real palettes, including Ember and Ahrefs's brand system, as the accent.
Blue #0000ff
shipped21 real palettes, including Robinhood's brand system and native Cybersecurity's brand system put Blue beside #21030d, as the supporting colour.
Blue Violet #8a2be2
shippedBlue Violet is paired with #21030d in 10 real palettes, including Gemstone and Twitch's brand system, as the supporting colour.
Real palettes that use #21030d
Tints & shades
Harmonies
Contrast
| #21030d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 19.38:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.08:1 | 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 #21030d as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Fonts for this mood
#21030d reads as warm, vivid, dark. The font library is tagged with the same vocabulary:
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 #21030d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/21030d-c49ca5-62cb75-2d211f-f1e9f0?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