Color
#210a57
#210a57rgb(33, 10, 87)hsl(258, 79%, 19%)oklch(0.246 0.124 286.6)Colors that go with #210a57
Charcoal, Royal Blue 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 #210a57: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #210a57's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #210a57 — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Blue #0000ff
shipped6 real palettes, including Penpot's brand system and Sketch's brand system put Blue beside #210a57, as the supporting colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #210a57: 6 real palettes, including SoFi's brand system and Open House, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #210a57: 10 real palettes, including Glacier and Blue Mono, as the accent.
Crimson #dc143c
shippedCrimson is paired with #210a57 in 8 real palettes, including Nintendo's brand system and Casper Sleep's brand system, as the supporting colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #210a57: 6 real palettes, including Kraken's brand system and Deep Water, as the accent.
Real palettes that use #210a57
Tints & shades
Harmonies
Contrast
| #210a57 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 16.86:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.25:1 | 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 #210a57 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
#210a57 reads as cool, 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 #210a57 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/210a57-ad9cc4-dfc44e-291f2d-e9ebf1?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