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
#66abfa
#66abfa
hex
#66abfargb
rgb(102, 171, 250)hsl
hsl(212, 94%, 69%)oklch
oklch(0.729 0.135 253)Closest name: Fennel Flower (#77aaff)Relative luminance 0.3885
Colors that go with #66abfa
Charcoal, Goldenrod and Amber 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 #36454f
neutralshippedCharcoal is the text near-black for #66abfa: softer than #000 and cool enough to feel like part of the same palette.
Goldenrod #daa520
complementaryshippedGoldenrod sits directly opposite #66abfa on the wheel — the strongest contrast one hue can give another, so use it small: a button, a link colour, one highlight.
Amber #ffbf00
shippedAmber is paired with #66abfa in 6 real palettes, including NBA's brand system and Salesforce's brand system, as the lead colour.
Blue #0000ff
shipped4 real palettes, including Warp's brand system and Spotify's brand system put Blue beside #66abfa, as the supporting colour.
Dark Orange #ff8c00
shippedDark Orange shows up next to #66abfa in 4 real palettes, including Learning App and Ahrefs's brand system, as the accent.
Denim #1560bd
shippedDesigners have shipped Denim with #66abfa: 6 real palettes, including Coca-Cola's brand system and Apple's brand system, as the accent.
Medium Sea Green #3cb371
shippedMedium Sea Green is paired with #66abfa in 4 real palettes, including Terminal and Spotify's brand system, as the lead colour.
Midnight Blue #191970
shipped8 real palettes, including Blue Mono and Kraken's brand system put Midnight Blue beside #66abfa, as the text colour against it.
Real palettes that use #66abfa
Tints & shades
Harmonies
Contrast
| #66abfa as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.39:1 | fail | fail | fail | |
Aaon black | 8.77:1 | pass | pass | pass | Passes AAA — no fix needed. |
Fixes keep hue and saturation and move lightness only, so the suggestion stays on-brand. Ratios are symmetric: the same numbers apply with #66abfa as the background.
Brands using this color
Palettes built around it
Fonts for this mood
#66abfa reads as cool, vivid, technical. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #66abfa
live endpointPoint 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.
endpoint
https://mcp.brandsweets.com/colors/mcpclaude mcp add --transport http brandsweets-colors https://mcp.brandsweets.com/colors/mcp
try this prompt
›analyze #66abfa and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/66abfa-9caac4-df564e-1f202d-e9f1f1?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