Color
#21409c
#21409crgb(33, 64, 156)hsl(225, 65%, 37%)oklch(0.408 0.154 265.6)Colors that go with #21409c
Charcoal, Sea Green and Steel 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.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #21409c: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #21409c — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Steel Blue #4682b4
analogousshippedSteel Blue is #21409c's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped8 real palettes, including Procter & Gamble's brand system and CVS's brand system put Blue beside #21409c, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #21409c: 4 real palettes, including Blue Mono and Gopro's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #21409c in 15 real palettes, including Walgreens's brand system and Behance's brand system, as the lead colour.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #21409c: 6 real palettes, including MLB's brand system and 3M's brand system, as the supporting colour.
Midnight Blue #191970
shipped18 real palettes, including Fintech Trust and Blue Mono put Midnight Blue beside #21409c, as that palette's text colour.
Real palettes that use #21409c
Tints & shades
Harmonies
Contrast
| #21409c as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 9.22:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.28:1 | 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 #21409c as the background.
Brands using this color
Fonts for this mood
#21409c reads as cool, vivid, technical. 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 #21409c and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/21409c-9ca1c4-df754e-221f2d-e9eff1?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