Color
#3878cc
#3878ccrgb(56, 120, 204)hsl(214, 59%, 51%)oklch(0.573 0.145 256.3)Colors that go with #3878cc
Charcoal, Copper 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 #3878cc: softer than #000 and cool enough to feel like part of the same palette.
Copper #b87333
complementaryshippedCopper sits directly opposite #3878cc 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 #3878cc in 11 real palettes, including Wired's brand system and Walmart's brand system, as the accent.
Blue #0000ff
shipped14 real palettes, including Readymag's brand system and Qualcomm's brand system put Blue beside #3878cc, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3878cc: 12 real palettes, including General Mills's brand system and Hershey's's brand system, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #3878cc: 5 real palettes, including NBA's brand system and Coca-Cola's brand system, as the accent.
Crimson #dc143c
shippedCrimson is paired with #3878cc in 17 real palettes, including NASCAR's brand system and Pizza Hut's brand system, as the supporting colour.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #3878cc: 8 real palettes, including Astro's brand system and Deep Water, as the supporting colour.
Real palettes that use #3878cc
Tints & shades
Harmonies
Contrast
| #3878cc as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 4.44:1 | fail | pass | fail | |
Aaon black | 4.73:1 | pass | 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 #3878cc as the background.
Brands using this color
Fonts for this mood
#3878cc 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 #3878cc and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3878cc-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