Blue Mono
Open in tool →One blue at four lightnesses — monochromatic in the colour-theory sense; the deep step is the text, the pale step the surface tint.
Color
#0d294frgb(13, 41, 79)hsl(215, 72%, 18%)oklch(0.283 0.077 257.1)Charcoal, Crimson and Sea Green 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 is the text near-black for #0d294f: softer than #000 and cool enough to feel like part of the same palette.
Crimson completes a triad with #0d294f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Sea Green completes a triad with #0d294f — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Sienna sits directly opposite #0d294f on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Slate Blue is #0d294f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Steel Blue is #0d294f's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Amber is paired with #0d294f in 8 real palettes, including Beach Hut and Southwest Airlines's brand system, as the supporting colour.
19 real palettes, including Monzo's brand system and Sketch's brand system put Blue beside #0d294f, as the accent.
| #0d294f as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 14.51:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.45:1 | 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 #0d294f as the background.
One blue at four lightnesses — monochromatic in the colour-theory sense; the deep step is the text, the pale step the surface tint.
#0d294f 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 #0d294f and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/0d294f-9ca8c4-df5d4e-201f2d-e9f0f1?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