Color
#301b64
#301b64rgb(48, 27, 100)hsl(257, 57%, 25%)oklch(0.299 0.121 290.3)Colors that go with #301b64
Charcoal, Royal 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 #301b64: softer than #000 and cool enough to feel like part of the same palette.
Royal Blue #4169e1
analogousshippedRoyal Blue is #301b64's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Blue #0000ff
shipped4 real palettes, including Sketch's brand system and Monzo's brand system put Blue beside #301b64, as the accent.
Cadet Blue #5f9ea0
shippedDesigners have shipped Cadet Blue with #301b64: 6 real palettes, including SoFi's brand system and Open House, as the supporting colour.
Cobalt Blue #0047ab
shippedDesigners have shipped Cobalt Blue with #301b64: 6 real palettes, including Blue Mono and Purina Pro Plan's brand system, as the lead colour.
Cornflower Blue #6495ed
shippedDesigners have shipped Cornflower Blue with #301b64: 4 real palettes, including Blue Mono and Peacock's brand system, as the supporting colour.
Crimson #dc143c
shippedCrimson is paired with #301b64 in 6 real palettes, including Casper Sleep's brand system and Marvel's brand system, as the lead colour.
Denim #1560bd
shippedDesigners have shipped Denim with #301b64: 14 real palettes, including Bank of America's brand system and Panasonic's brand system, as the accent.
Real palettes that use #301b64
Tints & shades
Harmonies
Contrast
| #301b64 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 14.32:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.47:1 | 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 #301b64 as the background.
Brands using this color
Fonts for this mood
#301b64 reads as cool, dark, luxury. 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 #301b64 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/301b64-ac9cc4-dfc24e-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