Palettes / Colors / #666C8A

#666C8A — Dusty Blue

#666C8A is a blue color we call Dusty Blue, closest to the named color SlateGray (#708090). It belongs to the blue family.

Color name

Closest CSS keyword: slategray (#708090) — not an exact match. CSS slategray gives you #708090, a different color; use #666C8A when you need this exact shade.

Sources: common names follow widely used color-name references; CSS keywords and their hex values follow the CSS Color specification.

#666C8A is a cool blue color associated with trust, calm and professionalism. It sits comfortably in the middle: usable for large areas in soft schemes, or as a supporting color beside something stronger.

Its strongest partner is its complement #8A8466; it also sits naturally between #667E8A and #72668A. In the palettes below you can see it working alongside real color combinations from our collection.

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Color values

RGB & CMYK percentages

Red 40% · Green 42% · Blue 54%

Cyan 26% · Magenta 22% · Yellow 0% · Key 46%

CMYK values are unprofiled approximations for screen reference — not a print-proofing guarantee.

Previews

CSS code for #666C8A

.text { color: #666C8A; }
.background { background-color: #666C8A; }
.border { border: 3px solid #666C8A; }
.text-rgb { color: rgb(102, 108, 138); }
.text-hsl { color: hsl(230, 15%, 47%); }
.text-shadow-hex { text-shadow: 4px 4px 2px #666C8A; }
.text-shadow-rgba { text-shadow: 4px 4px 2px rgba(102, 108, 138, 0.8); }
.box-shadow-hex { box-shadow: 1px 1px 3px 2px #666C8A; }
.box-shadow-rgba { box-shadow: 1px 1px 3px 2px rgba(102, 108, 138, 0.8); }

HTML: <p style="color:#666C8A">Text here</p> · <div style="background-color:#666C8A">Div content here</div>

Shades of #666C8A

Tints of #666C8A

Tones of #666C8A

Color harmonies

Complementary — #8A8466:

Analogous:

Triadic:

Contrast & accessibility

Best text color on #666C8A: #FFFFFF.

Semi-transparent (opacity) text on #666C8A

Text set with opacity blends into the background, so its real contrast is lower than the solid ratios above. Choose a text color and an opacity to see the blended color and its true ratio:

How #666C8A looks with color blindness

Simulated with standard Machado color-vision-deficiency matrices — useful when this color carries meaning in charts, maps or interfaces:

Closest design-system colors

The nearest matches in the Tailwind CSS, Material Design and Bootstrap palettes — handy when you need a framework class instead of a raw hex:

Palettes with a similar color

These palettes use a close neighbour of #666C8A rather than the exact color:

Similar colors

The closest colors that actually appear in our palette collection — click any to open its page:

Browse neighbouring colors

← #666C89  ·  #666C8B →

Frequently asked questions

What color is #666C8A?

#666C8A is Dusty Blue, a blue color (RGB 102, 108, 138). Its closest standard named color is SlateGray.

What is the RGB and HSL of #666C8A?

#666C8A is RGB 102, 108, 138 — HSL 230°, 15%, 47% — CMYK 26%, 22%, 0%, 46%.

What colors go with #666C8A?

Its complement is #8A8466; analogous partners are #667E8A and #72668A. It also appears in 6+ palettes in our collection.

Can I use #666C8A for text?

White text on #666C8A has a contrast ratio of 5.15:1 (passes WCAG AA); black text gives 4.08:1.