Color
#3f307e
#3f307ergb(63, 48, 126)hsl(252, 45%, 34%)oklch(0.372 0.126 287.4)Colors that go with #3f307e
Charcoal, Steel Blue and 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 #3f307e: softer than #000 and cool enough to feel like part of the same palette.
Steel Blue #4682b4
analogousshippedSteel Blue is #3f307e's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped5 real palettes, including Alaska Airlines's brand system and Procter & Gamble's brand system put Blue beside #3f307e, as the accent.
Crimson #dc143c
shippedCrimson is paired with #3f307e in 5 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #3f307e: 10 real palettes, including Hasbro's brand system and Warbyparker's brand system, as the supporting colour.
Powder Blue #b0e0e6
shippedDesigners have shipped Powder Blue with #3f307e: 4 real palettes, including Glacier and First Snow, as the supporting colour.
Royal Blue #4169e1
shippedRoyal Blue is paired with #3f307e in 7 real palettes, including Discord's brand system and Confluent's brand system, as the lead colour.
Taupe #483c32
shippedTaupe is paired with #3f307e in 4 real palettes, including Gillette's brand system and Datadog's brand system, as the lead colour.
Real palettes that use #3f307e
Tints & shades
Harmonies
Contrast
| #3f307e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 10.85:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.94:1 | 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 #3f307e 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
#3f307e 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 #3f307e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/3f307e-a99cc4-dfb64e-281f2d-e9ecf1?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