Blueprint
Open in tool →Cyan and indigo on navy is the developer-tool look; amber is the only warm note, so it always reads as 'attention'.
Color
#151b28
#151b28
hex
#151b28rgb
rgb(21, 27, 40)hsl
hsl(221, 31%, 12%)oklch
oklch(0.223 0.027 265.1)Closest name: Dark Knight (#151931)Relative luminance 0.011
Tints & shades
Harmonies
Contrast
| #151b28 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 17.22:1 | pass | pass | pass | Passes AAA — no fix needed. |
Aaon black | 1.22:1 | 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 #151b28 as the background.
Brands using this color
Palettes built around it
Indigo SaaS
Open in tool →The dependable indigo-and-emerald B2B pairing: indigo for primary actions, emerald reserved for success states.
Slate Workspace
Open in tool →Slate on slate with a single blue — the productivity-app look where the interface disappears behind the work.
Clinic
Open in tool →Teal reads clinical without the coldness of pure blue; the coral accent adds warmth for reassurance moments.
Arctic
Open in tool →Navy type on white with an ice-blue accent: crisp and corporate without going grey.
Cobalt Pop
Open in tool →One deep cobalt and one hot pink on white — a two-accent system for launches and campaign pages that need punch.
Fonts for this mood
#151b28 reads as cool, muted, dark. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #151b28
live endpointPoint any MCP client at the shared colors endpoint and your agent gets the same engine as this page — generate_palette, check_contrast, analyze_color — read-only, no key. Every palette it proposes comes with a /palettes/new/… link: open it, lock what you like, paste the link back.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #151b28 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/151b28-9ca4c4-df6b4e-211f2d-e9eff1?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