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
#669ff5
#669ff5
hex
#669ff5rgb
rgb(102, 159, 245)hsl
hsl(216, 88%, 68%)oklch
oklch(0.701 0.141 258.4)Closest name: cornflowerblue (#6495ed)Relative luminance 0.3421
Colors that go with #669ff5
Charcoal, Peru 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 #669ff5: softer than #000 and cool enough to feel like part of the same palette.
Peru #cd853f
complementaryshippedPeru sits directly opposite #669ff5 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 #669ff5 in 6 real palettes, including NBA's brand system and Ahrefs's brand system, as the lead colour — a combination designers have actually shipped, not a computed rotation.
Blue #0000ff
shippedBlue is paired with #669ff5 in 5 real palettes, including Spotify's brand system and Unity's brand system, as the accent — a combination designers have actually shipped, not a computed rotation.
Dark Orange #ff8c00
shippedDark Orange is paired with #669ff5 in 4 real palettes, including Ahrefs's brand system and Learning App, as the lead colour — a combination designers have actually shipped, not a computed rotation.
Denim #1560bd
shippedDenim is paired with #669ff5 in 6 real palettes, including Coca-Cola's brand system and Apple's brand system, as the accent — a combination designers have actually shipped, not a computed rotation.
Emerald Green #50c878
shippedEmerald Green is paired with #669ff5 in 4 real palettes, including Playground and Obsidian's brand system, as the accent — a combination designers have actually shipped, not a computed rotation.
Medium Sea Green #3cb371
shippedMedium Sea Green is paired with #669ff5 in 4 real palettes, including Terminal and Spotify's brand system, as the lead colour — a combination designers have actually shipped, not a computed rotation.
Real palettes that use #669ff5
Tints & shades
Harmonies
Contrast
| #669ff5 as text | Ratio | AA | AA large | AAA | Fix |
|---|---|---|---|---|---|
Aaon white | 2.68:1 | fail | fail | fail | |
Aaon black | 7.84:1 | 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 #669ff5 as the background.
Brands using this color
No public brand in the corpus uses this exact color yet. Extract a brand to add one.
Palettes built around it
Fonts for this mood
#669ff5 reads as cool, vivid, technical. The font library is tagged with the same vocabulary:
mcpConnect your agent — build around #669ff5
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 #669ff5 and generate a 5-color palette that keeps it as the primary; give me the /palettes/new link
tool url
/palettes/new/669ff5-9ca7c4-df5f4e-201f2d-e9f0f1?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