Color
#3901df
#3901dfrgb(57, 1, 223)hsl(255, 99%, 44%)oklch(0.43 0.271 274.5)Colors that go with #3901df
Charcoal, Cobalt Blue and Cornflower Blue 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 #3901df: softer than #000 and cool enough to feel like part of the same palette.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3901df: 8 real palettes, including Unilever's brand system and CVS's brand system, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #3901df: 4 real palettes, including Qualcomm's brand system and Canva's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3901df in 4 real palettes, including Dunkin''s brand system and Tim Hortons's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #3901df: 5 real palettes, including Unilever's brand system and Activision's brand system, as the accent.
Dodger Blue #1e90ff
shippedDesigners have shipped Dodger Blue with #3901df: 6 real palettes, including Cargo's brand system and Readymag's brand system, as the lead colour.
Midnight Blue #191970
shipped9 real palettes, including Monzo's brand system and Sketch's brand system put Midnight Blue beside #3901df, as the lead colour.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3901df — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Real palettes that use #3901df
Tints & shades
Harmonies
Contrast
| #3901df as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 9.36:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.24:1 | 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 #3901df 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
#3901df reads as cool, vivid, technical. 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 #3901df and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3901df-ab9cc4-dfbd4e-291f2d-e9ebf1?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