#666F63

#666F63

Color Values

HEX

#666F63

RGB

102, 111, 99

HSL

105.0, 5.7%, 41.2%

HSV

105.0, 10.8%, 43.5%

CMYK

8.1%, 0.0%, 10.8%, 56.5%

OKLCH

0.5303 0.0214 137.8

Properties

Cool Dark Nearest: RAL 7023 Concrete Grey

Color Harmonies

Complementary

#666F63

#6C636F

Analogous

#6C6F63

#636F66

#666F63

Triadic

#666F63

#63666F

#6F6366

Split Complementary

#666F63

#66636F

#6F636C

Tetradic

#666F63

#636C6F

#6C636F

#6F6663

Color Blindness Simulation

Original

#666F63

Protanopia

#6A6A66

Deuteranopia

#696967

Tritanopia

#666869

Achromatopsia

#6C6C6C

CSS Usage

background-color: #666F63;
color: #666F63;
border-color: #666F63;
Nearest Tailwind: Stone 500 #78716C

Tailwind Shades

50
#F7F8F7
100
#EDEEEC
200
#DADDD9
300
#C0C5BE
400
#9EA69B
500
#7C8778
600
#636C60
700
#4F564D
800
#3E433C
900
#2F332E
950
#1E201D

Contrast Checker

Text on white

5.23:1

AA Pass AAA Fail

Text on black

4.02:1

AA Fail AAA Fail

Related Articles

Tutorials

Building a Color Picker Web Component from Scratch

Feb 20, 2026
Tutorials

Web Color Performance: Gradients, Shadows, and Filters

Feb 19, 2026
Tutorials

Tailwind CSS Colors: Complete Shade System Guide

Feb 19, 2026