Color
#3f66ca
#3f66cargb(63, 102, 202)hsl(223, 57%, 52%)oklch(0.536 0.162 265.3)Colors that go with #3f66ca
Charcoal, Sea Green and Amber 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 #3f66ca: softer than #000 and cool enough to feel like part of the same palette.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3f66ca — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Amber #ffbf00
shippedAmber is paired with #3f66ca in 10 real palettes, including Wikipedia's brand system and Warner Bros.'s brand system, as the accent.
Blue #0000ff
shipped16 real palettes, including Pixar's brand system and Activision's brand system put Blue beside #3f66ca, as the accent.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3f66ca: 13 real palettes, including Unilever's brand system and Intel's brand system, as the lead colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #3f66ca: 7 real palettes, including Coca-Cola's brand system and NBA's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3f66ca in 19 real palettes, including Pizza Hut's brand system and Netflix's brand system, as the supporting colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #3f66ca: 7 real palettes, including Astro's brand system and Venmo's brand system, as the supporting colour.
Real palettes that use #3f66ca
Tints & shades
Harmonies
Contrast
| #3f66ca as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 5.3:1 | pass | pass | fail |
|
Aaon black | 3.96:1 | 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 #3f66ca as the background.
Brands using this color
Fonts for this mood
#3f66ca 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 #3f66ca and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f66ca-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