Color
#3f405a
#3f405argb(63, 64, 90)hsl(238, 18%, 30%)oklch(0.382 0.044 282.4)Colors that go with #3f405a
Steel Blue, Teal and Dark Olive 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.
Steel Blue #4682b4
analogousshippedSteel Blue is #3f405a's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Teal #008080
triadicshippedTeal completes a triad with #3f405a — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Dark Olive Green #556b2f
complementaryshippedDark Olive Green sits directly opposite #3f405a on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped10 real palettes, including Alaska Airlines's brand system and Jeep's brand system put Blue beside #3f405a, as the accent.
Blush Pink #e8b4b8
shipped4 real palettes, including Nursery and Garden Wedding put Blush Pink beside #3f405a, as the lead colour.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #3f405a: 5 real palettes, including Paper & Pine and Clean Beauty, as the supporting colour.
Copper #b87333
shippedDesigners have shipped Copper with #3f405a: 6 real palettes, including Notion's brand system and Bramble.
White Smoke #f5f5f5
neutralWhite Smoke is the surface for #3f405a: a clean near-white with no warm cast, so the cool hue stays clear instead of drifting muddy.
Real palettes that use #3f405a
Tints & shades
Harmonies
Contrast
| #3f405a as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 10.04:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.09:1 | 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 #3f405a 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
#3f405a reads as cool, muted, 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 #3f405a and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f405a-9f9cc4-df944e-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