#818399

#818399

Color Values

HEX

#818399

RGB

129, 131, 153

HSL

235.0, 10.5%, 55.3%

HSV

235.0, 15.7%, 60.0%

CMYK

15.7%, 14.4%, 0.0%, 40.0%

OKLCH

0.6159 0.0332 281.3

Properties

Cool Light Nearest: lightslategrey

Color Harmonies

Complementary

#818399

#999781

Analogous

#818F99

#8B8199

#818399

Triadic

#818399

#998183

#839981

Split Complementary

#818399

#998B81

#8F9981

Tetradic

#818399

#99818F

#999781

#81998B

Color Blindness Simulation

Original

#818399

Protanopia

#828294

Deuteranopia

#828292

Tritanopia

#818F8F

Achromatopsia

#848484

CSS Usage

background-color: #818399;
color: #818399;
border-color: #818399;
Nearest Tailwind: Slate 500 #64748B

Tailwind Shades

50
#F7F7F8
100
#ECECEF
200
#D8D8DF
300
#BBBCC8
400
#9798AB
500
#72748D
600
#5B5D71
700
#494A5A
800
#393A46
900
#2C2D35
950
#1C1C21

Contrast Checker

Text on white

3.72:1

AA Fail AAA Fail

Text on black

5.64:1

AA Pass 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