Color
#3f558d
#3f558drgb(63, 85, 141)hsl(223, 38%, 40%)oklch(0.459 0.096 266.5)Colors that go with #3f558d
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 #3f558d: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3f558d — 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 #3f558d's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped4 real palettes, including CVS's brand system and Pixar's brand system put Blue beside #3f558d, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3f558d in 9 real palettes, including Amazon's brand system and Target : Expect More. Pay Less.'s brand system, as the supporting colour.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #3f558d: 6 real palettes, including Campbell's's brand system and AT&T's brand system, as the supporting colour.
Goldenrod #daa520
shippedGoldenrod shows up next to #3f558d in 4 real palettes, including Open House and Sapphire & Gold, as the accent.
Midnight Blue #191970
shipped12 real palettes, including FIFA's brand system and First Snow put Midnight Blue beside #3f558d, as the lead colour.
Real palettes that use #3f558d
Tints & shades
Harmonies
Contrast
| #3f558d as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.25:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.9:1 | 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 #3f558d 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
#3f558d 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 #3f558d and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f558d-9ca3c4-df704e-211f2d-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