About

Every color displayed on screen resolves to a numeric triplet of red, green, and blue channel intensities in the range 0 - 255. Hexadecimal notation compresses this triplet into a six-character string prefixed with #, where each pair encodes one channel in base-16. A miscoded hex value in CSS or SVG silently fails to render, defaulting to black or inherited color and breaking visual hierarchy without throwing an error. This tool parses any hex input, validates it against the 16,777,216 possible sRGB values, and converts it to RGB, HSL, and CMYK simultaneously. It also computes WCAG 2.1 relative luminance and contrast ratios against white and black backgrounds so you can verify accessibility compliance before shipping.

Formulas

A hex color string #RRGGBB encodes three channel values. Each two-character pair is a base-16 integer converted to decimal:

R = 16 × R₁ + R₀

where R₁ is the high nibble and R₀ is the low nibble, both in range 0 - 15. The same applies to G and B channels.

RGB to HSL conversion normalizes channels to 0 - 1, then computes:

L = C_max + C_min2

S = Δ1 − |2L − 1|

where Δ = C_max − C_min. Hue H depends on which channel is C_max, computed as a 60° sector offset.

WCAG 2.1 relative luminance uses linearized sRGB:

L = 0.2126R_lin + 0.7152G_lin + 0.0722B_lin

where each linear channel C_lin is obtained by applying the sRGB transfer function: if C_srgb ≤ 0.04045, then C_lin = C_srgb12.92, otherwise C_lin = ((C_srgb + 0.055) ÷ 1.055)^2.4. Contrast ratio = L₁ + 0.05L₂ + 0.05 where L₁ is the lighter luminance.

Reference Data

Color Name	Hex Code	R	G	B	HSL	Usage Context
White	#FFFFFF	255	255	255	0°, 0%, 100%	Backgrounds, whitespace
Black	#000000	0	0	0	0°, 0%, 0%	Text, borders
Red	#FF0000	255	0	0	0°, 100%, 50%	Errors, alerts
Green	#00FF00	0	255	0	120°, 100%, 50%	Success states
Blue	#0000FF	0	0	255	240°, 100%, 50%	Links, primary actions
Coral	#FF7F50	255	127	80	16°, 100%, 66%	CTAs, warm accents
Teal	#008080	0	128	128	180°, 100%, 25%	Professional themes
Gold	#FFD700	255	215	0	51°, 100%, 50%	Highlights, premium
Slate Gray	#708090	112	128	144	210°, 13%, 50%	Secondary text
Indigo	#4B0082	75	0	130	275°, 100%, 25%	Creative branding
Tomato	#FF6347	255	99	71	9°, 100%, 64%	Warning, attention
Medium Purple	#9370DB	147	112	219	260°, 60%, 65%	Creative UI
Dark Cyan	#008B8B	0	139	139	180°, 100%, 27%	Medical, science UI
Chocolate	#D2691E	210	105	30	25°, 75%, 47%	Earth tones, organic
Steel Blue	#4682B4	70	130	180	207°, 44%, 49%	Corporate, dashboards
Lime Green	#32CD32	50	205	50	120°, 61%, 50%	Eco, nature themes
Hot Pink	#FF69B4	255	105	180	330°, 100%, 71%	Fashion, playful UI
Midnight Blue	#191970	25	25	112	240°, 64%, 27%	Dark themes, headers
Light Salmon	#FFA07A	255	160	122	17°, 100%, 74%	Soft CTA, food apps
Rebecca Purple	#663399	102	51	153	270°, 50%, 40%	CSS named color (2014)

Frequently Asked Questions

A 3-digit hex code like #F0A is shorthand where each digit is doubled: #FF00AA. The 6-digit form provides full precision with 16,777,216 possible colors. Some tools also support 8-digit hex (#RRGGBBAA) where the last two characters encode alpha transparency from 00 (fully transparent) to FF (fully opaque).

Hex codes encode sRGB channel values. Each pair maps linearly to 0-255 integer intensity per channel. This is gamma-encoded sRGB, not linear light. Calculations requiring perceptual accuracy (luminance, color difference) must first linearize these values using the sRGB transfer function with the 0.04045 threshold and 2.4 gamma exponent.

Display color depends on the monitor's color profile (ICC), backlight technology, and gamma calibration. A hex value #6C8EEF defines an sRGB coordinate, but an uncalibrated wide-gamut display may render it more saturated. Use hardware colorimeters and ICC profiles for cross-device consistency. The hex number itself is correct; the rendering pipeline introduces variance.

WCAG 2.1 Level AA requires a minimum contrast ratio of 4.5:1 for normal text (below 18pt or 14pt bold) and 3:1 for large text. Level AAA requires 7:1 for normal text and 4.5:1 for large text. These ratios are computed from relative luminance values derived from linearized sRGB channels, not from perceived brightness alone.

RGB-to-CMYK conversion computes the Key (black) channel as K = 1 − max(R', G', B') where R' = R/255. Then C = (1 − R' − K) / (1 − K), and similarly for M and Y. This is a mathematical approximation. Actual print CMYK depends on ink profiles, paper stock, and press calibration. For production work, use ICC color profiles and soft-proofing in dedicated prepress software.

No. Hex notation is limited to the sRGB gamut: 256 levels per channel, totaling 16,777,216 colors. Display P3, Adobe RGB, and Rec. 2020 gamuts exceed sRGB. CSS now supports these via the color() function (e.g., color(display-p3 0.42 0.56 0.94)). Hex codes cannot encode these wider-gamut values.