Dusk
Open in tool →Slate blue with a copper accent — calm, professional, slightly editorial; suits consultancies and journals.
Color
#3c5e8b
#3c5e8b
hex
#3c5e8brgb
rgb(60, 94, 139)hsl
hsl(214, 40%, 39%)oklch
oklch(0.477 0.083 255.8)Closest name: Dusk (#4e5481)Relative luminance 0.1083
Colors that go with #3c5e8b
Charcoal, Sea Green and Sienna 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 #3c5e8b: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3c5e8b — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Sienna #a0522d
complementaryshippedSienna sits directly opposite #3c5e8b on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Amber #ffbf00
shippedAmber is paired with #3c5e8b in 7 real palettes, including McDonald's's brand system and Lemon Squeezy's brand system, as the lead colour.
Blue #0000ff
shipped6 real palettes, including Activision's brand system and Tesco's brand system put Blue beside #3c5e8b, as the accent.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3c5e8b: 6 real palettes, including Fintech Trust and Unilever's brand system, as the lead colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #3c5e8b: 4 real palettes, including Coca-Cola's brand system and Gopro's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3c5e8b in 17 real palettes, including Costco's brand system and McDonald's's brand system, as the lead colour.
Real palettes that use #3c5e8b
Tints & shades
Harmonies
Contrast
| #3c5e8b as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 6.63:1 | pass | pass | fail |
|
Aaon black | 3.17:1 | fail | pass | fail |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #3c5e8b as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#3c5e8b reads as cool, modern. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #3c5e8b
live endpointPoint 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.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #3c5e8b and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/3c5e8b-9ca9c4-df5a4e-1f1f2d-e9f0f1?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