#660000

Color #660000

Web safe

A vivid, highly saturated dark red.

Closest named color Maroon #800000 · ΔE 12.68 Nearest Tailwind class red-900 #82181a · ΔE 6.6

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Conversions

HEX

#660000

RGB

rgb(102, 0, 0)

HSL

hsl(0, 100%, 20%)

HSV / HSB

hsv(0, 100%, 40%)

CMYK

cmyk(0%, 100%, 100%, 60%)

LAB

lab(19.33, 40.87, 29.66)

LCH

lch(19.33, 50.5, 35.97)

OKLCH

oklch(32%, 0.1314, 29.24)

HWB

hwb(0, 0%, 60%)

Harmony colors

Complementary

#006666

Analogous

#660033

#660000

#663300

Triadic

#660000

#006600

#000066

Split-complementary

#660000

#006633

#003366

Tetradic

#660000

#666600

#006666

#000066

Square

#660000

#336600

#006666

#330066

Shades

Color #660000 mixed toward black.

#550000

#440000

#330000

#220000

#110000

Tints

Color #660000 mixed toward white.

#aa0000

#ee0000

#ff3333

#ff7777

#ffbbbb

Tones

Color #660000 mixed toward gray.

#5e0808

#551111

#4d1a1a

#442222

#3c2b2b

Accessibility

Aa White text on this color

13.42:1

Aa Black text on this color

1.56:1

White text reads better on this background (13.42:1). That passes WCAG AAA (≥7:1) for normal-size text.

Under color vision deficiencies

Protanopia

#4e4d00 · ΔE 36.7

Deuteranopia

#515600 · ΔE 40.2

Tritanopia

#640000 · ΔE 0.5

Achromatopsia

#2f2f2f · ΔE 24.6

Left half is the original, right half is the simulated appearance. See all 8 vision types →

Code

CSS

background-color: #660000;

Tailwind (arbitrary value)

bg-[#660000]

Related colors

Red #ff0000

Maroon #800000

Black #000000

Brown #a52a2a

Dark Gray #a9a9a9

Dark Red #8b0000

Frequently asked questions

#660000 (#660000) is rgb(102, 0, 0) in RGB.

Yes, #660000 is one of the 216 web-safe colors — every channel is a multiple of 51.

Related tools

Colors

HEX to RGB Converter

Convert any HEX color code to its RGB and HSL equivalents, live, with copy-to-clipboard values.

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Contrast Checker

Check the WCAG contrast ratio between any two colors, live, with AA/AAA pass-fail results.

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Palette Generator

Generate complementary, analogous, triadic, split-complementary, tetradic, square, and monochromatic palettes from any base color.

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Build something with this color

Generate a full palette from #660000, or check how it holds up for accessibility.

Generate a palette → Check contrast