Playground
Open in tool →Orange, blue and green — the colors of playground equipment; loud, cheerful, obviously for kids.
Color
#3981f3
#3981f3
hex
#3981f3rgb
rgb(57, 129, 243)hsl
hsl(217, 89%, 59%)oklch
oklch(0.618 0.186 259.4)Closest name: Azure (#007fff)Relative luminance 0.2304
Colors that go with #3981f3
Charcoal, Crimson 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 #3981f3: softer than #000 and cool enough to feel like part of the same palette.
Crimson #dc143c
triadicshippedCrimson completes a triad with #3981f3 — 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 #3981f3 in 12 real palettes, including Google's brand system and Heatwave, as the accent.
Blue #0000ff
shipped13 real palettes, including Readymag's brand system and Cargo's brand system put Blue beside #3981f3, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3981f3: 11 real palettes, including Carrefour's brand system and Behance's brand system, as the accent.
Deep Sky Blue #00bfff
shippedDesigners have shipped Deep Sky Blue with #3981f3: 10 real palettes, including Patreon's brand system and Venmo's brand system, as the supporting colour.
Denim #1560bd
shippedDesigners have shipped Denim with #3981f3: 18 real palettes, including Coursera's brand system and Venmo's brand system, as the accent.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #3981f3: 5 real palettes, including Honda's brand system and Bose's brand system, as the supporting colour.
Real palettes that use #3981f3
Tints & shades
Harmonies
Contrast
| #3981f3 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 3.74:1 | fail | pass | fail | |
Aaon black | 5.61:1 | 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 #3981f3 as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#3981f3 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #3981f3
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 #3981f3 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/3981f3-9ca7c4-df624e-201f2d-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