Color
#300057
#300057rgb(48, 0, 87)hsl(273, 100%, 17%)oklch(0.255 0.135 301.3)Colors that go with #300057
Cadet Blue, Cobalt Blue and Denim 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.
Cadet Blue #5f9ea0
shippedCadet Blue is paired with #300057 in 4 real palettes, including Open House and Arctic, as the supporting colour — a combination designers have actually shipped, not a computed rotation.
Cobalt Blue #0047ab
shippedCobalt Blue is paired with #300057 in 4 real palettes, including Blue Mono and Glacier, as the lead colour — a combination designers have actually shipped, not a computed rotation.
Denim #1560bd
shippedDenim is paired with #300057 in 4 real palettes, including Open House and Campus, as the lead colour — a combination designers have actually shipped, not a computed rotation.
Royal Blue #4169e1
analogousshippedRoyal Blue is #300057's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Slate Gray #708090
shippedSlate Gray is paired with #300057 in 4 real palettes, including Campus and Clinic, as the supporting colour — a combination designers have actually shipped, not a computed rotation.
Steel Blue #4682b4
shippedSteel Blue is paired with #300057 in 4 real palettes, including Deep Water and Glacier, as the supporting colour — a combination designers have actually shipped, not a computed rotation.
Olive Green #808000
complementaryOlive Green sits directly opposite #300057 on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #300057: softer than #000 and cool enough to feel like part of the same palette.
Real palettes that use #300057
Tints & shades
Harmonies
Contrast
| #300057 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 16.62:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.26:1 | 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 #300057 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
#300057 reads as cool, vivid, dark. 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 #300057 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/300057-b79cc4-c4cb62-2d1f2d-eae9f1?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