Color
#151b9e
#151b9ergb(21, 27, 158)hsl(237, 77%, 35%)oklch(0.344 0.2 268)Colors that go with #151b9e
Crimson, Steel 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.
Crimson #dc143c
triadicshippedCrimson completes a triad with #151b9e — three hues spaced evenly round the wheel, the classic way to get energy into a palette without a clash.
Steel Blue #4682b4
analogousshippedSteel Blue is #151b9e's neighbour on the wheel, so the two read as one family — use it for hover states, gradients and secondary surfaces.
Denim #1560bd
shippedDesigners have shipped Denim with #151b9e: 6 real palettes, including Warbyparker's brand system and Unilever's brand system, as the accent.
Royal Blue #4169e1
shippedRoyal Blue is paired with #151b9e in 7 real palettes, including Nivea's brand system and Discord's brand system, as the supporting colour.
Olive Green #808000
complementaryOlive Green sits directly opposite #151b9e on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Blue #0000ff
shipped3 real palettes, including Procter & Gamble's brand system and Pfizer's brand system put Blue beside #151b9e, as the supporting colour.
Charcoal #36454f
neutralshippedCharcoal is the text near-black for #151b9e: softer than #000 and cool enough to feel like part of the same palette.
Firebrick #b22222
shippedDesigners have shipped Firebrick with #151b9e: 3 real palettes, including Nintendo's brand system and 3M's brand system, as the accent.
Real palettes that use #151b9e
Tints & shades
Harmonies
Contrast
| #151b9e as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 12.48:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.68:1 | 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 #151b9e as the background.
Brands using this color
Fonts for this mood
#151b9e 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 #151b9e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
/palettes/new/151b9e-9f9cc4-df924e-251f2d-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