Color
#3729ff
#3729ffrgb(55, 41, 255)hsl(244, 100%, 58%)oklch(0.489 0.289 271)Colors that go with #3729ff
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 #3729ff: softer than #000 and cool enough to feel like part of the same palette.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #3729ff: 6 real palettes, including Zillow's brand system and CVS's brand system, as the supporting colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #3729ff: 4 real palettes, including Qualcomm's brand system and Spotify's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #3729ff in 7 real palettes, including Coinbase's brand system and Dunkin''s brand system.
Dodger Blue #1e90ff
shippedDesigners have shipped Dodger Blue with #3729ff: 7 real palettes, including Unity's brand system and Cargo's brand system, as the lead colour.
Medium Sea Green #3cb371
shippedMedium Sea Green is paired with #3729ff in 5 real palettes, including Unity's brand system and Indigo SaaS, as the accent.
Midnight Blue #191970
shipped8 real palettes, including Penpot's brand system and Monzo's brand system put Midnight Blue beside #3729ff, as the lead colour.
Sea Green #2e8b57
triadicshippedSea Green completes a triad with #3729ff — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Real palettes that use #3729ff
Tints & shades
Harmonies
Contrast
| #3729ff as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 7.18:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 2.92:1 | 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 #3729ff as the background.
Brands using this color
Fonts for this mood
#3729ff 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 #3729ff and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3729ff-a39cc4-dfa24e-261f2d-e9edf1?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