Color

#231d90

#231d90
hex#231d90
rgbrgb(35, 29, 144)
hslhsl(243, 66%, 34%)
oklchoklch(0.337 0.178 273.6)
Closest name: Dramatic Blue (#240093)Relative luminance 0.0325

Colors that go with #231d90

Steel Blue, Blue and Charcoal 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 →

#8a901d

#1d5190 · #5c1d90

#90231d · #1d9023

Split-complementary

Open in tool →

#905c1d · #51901d

#901d51 · #8a901d · #1d905c

Contrast

#231d90 as textRatioAAAA largeAAAFix
Aaon white
12.73:1passpasspassPasses AAA — no fix needed.
Aaon black
1.65:1failfailfail
  • AA: use #6d67e0 as the text (4.67:1)
  • AAA: use #918de8 as the text (7.18:1)
  • AA: or shift the background to #9c9c9c (4.64:1)
  • AAA: or shift the background to #c2c2c2 (7.15:1)

Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #231d90 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

#231d90 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:

mcpConnect your agent — build around #231d90
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 #231d90 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link

tool url/palettes/new/231d90-a39cc4-dfa04e-261f2d-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