Color

#151b7e

#151b7e
hex#151b7e
rgbrgb(21, 27, 126)
hslhsl(237, 71%, 29%)
oklchoklch(0.305 0.161 269.6)
Closest name: midnightblue (#191970)Relative luminance 0.0245

Colors that go with #151b7e

Steel Blue, Charcoal and Cobalt 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.

Tints & shades

Every swatch is its own page — click any to analyze it.

Harmonies

Complementary

Open in tool →

#7e7915

#154f7e · #45157e

#7e151b · #1b7e15

Split-complementary

Open in tool →

#7e4515 · #4f7e15

#7e154f · #7e7915 · #157e45

Contrast

#151b7e as textRatioAAAA largeAAAFix
Aaon white
14.09:1passpasspassPasses AAA — no fix needed.
Aaon black
1.49:1failfailfail
  • AA: use #6269e4 as the text (4.66:1)
  • AAA: use #898eeb as the text (7.13:1)
  • AA: or shift the background to #949494 (4.65:1)
  • AAA: or shift the background to #b8b8b8 (7.11:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #151b7e as the background.

Brands using this color

Fonts for this mood

#151b7e reads as cool, vivid, dark. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #151b7e
live endpoint

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.

endpointhttps://mcp.brandsweets.com/colors/mcp
claude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt

analyze #151b7e and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/151b7e-9f9cc4-df924e-251f2d-e9edf1?lock=0&style=vibrant

Want the agent to remember your picks and write them into a living brand? Create a free BrandSweets workspace.

Machine-readable: color.md