Color
#3f409d
#3f409drgb(63, 64, 157)hsl(239, 43%, 43%)oklch(0.427 0.148 277.7)Colors that go with #3f409d
Charcoal, Steel Blue and Crimson 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 #3f409d: softer than #000 and cool enough to feel like part of the same palette.
Steel Blue #4682b4
analogousshippedSteel Blue is #3f409d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Crimson #dc143c
shippedCrimson is paired with #3f409d in 6 real palettes, including Chase's brand system and Behance's brand system, as the accent — a combination designers have actually shipped, not a computed rotation.
Midnight Blue #191970
shippedMidnight Blue is paired with #3f409d in 9 real palettes, including Blue Mono and Fintech Trust, as the text colour against it — a combination designers have actually shipped, not a computed rotation.
Royal Blue #4169e1
shippedRoyal Blue is paired with #3f409d in 9 real palettes, including Carrefour's brand system and NHL's brand system, as the supporting colour — a combination designers have actually shipped, not a computed rotation.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3f409d — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Taupe #483c32
shippedTaupe is paired with #3f409d in 4 real palettes, including Datadog's brand system and Dusk, as the text colour against it — a combination designers have actually shipped, not a computed rotation.
Dark Olive Green #556b2f
complementaryDark Olive Green sits directly opposite #3f409d on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Real palettes that use #3f409d
Tints & shades
Harmonies
Contrast
| #3f409d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 8.64:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.43:1 | 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 #3f409d 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
#3f409d reads as cool, modern. 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 #3f409d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f409d-a09cc4-df964e-251f2d-e9edf1?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