Color Converter
Free online color converter. Convert HEX, RGB, RGBA, HSL, CMYK, LAB, OKLCH & CSS color codes instantly with live preview, WCAG contrast checker & developer exports.
Live Color Preview Cards & Swatches
CMYK Print Note: RGB-to-CMYK conversion is an approximate mathematical conversion. Actual printed colors can vary by printer, ink, paper, and ICC color profile.
HSV / HSB Model: HSV and HSB refer to the same color model terminology used in software like Adobe Photoshop and Sketch.
Overview & What is a Color Converter
The Color Converter by ToolMono is an enterprise-grade, browser-based color transformation workspace engineered for web developers, UI/UX designers, front-end engineers, and graphic artists. Operating in digital design requires translating color coordinates between distinct mathematical representations—ranging from legacy 6-digit HEX codes and RGB/RGBA to print-ready CMYK inks and modern CSS Level 4 OKLCH color spaces.
Whether you are building accessible component libraries, generating design tokens for Figma, upgrading CSS stylesheets, or preparing artwork for commercial printing, ToolMono delivers instant, high-precision mathematical conversions. Combine this tool with JSON Formatter for managing design token schemas, Image Converter for media production, and Base64 Encoder for inline SVG styling.
Supported Color Formats & Color Spaces
ToolMono supports instant 2-way conversion across 14 digital and physical color formats:
HEX & HEX8 (#RRGGBB / #RRGGBBAA)
Hexadecimal 6-digit and 8-digit representations of sRGB light levels. Universal standard for web stylesheets, HTML, and graphics software.
RGB & RGBA (Red, Green, Blue, Alpha)
Additive color channels (0–255) specifying emitted light intensity on digital displays, accompanied by 0–1 alpha channel opacity.
HSL & HSLA (Hue, Saturation, Lightness)
Cylindrical coordinate representation of RGB. Hue (0–360°), Saturation (0–100%), and Lightness (0–100%) offer human-intuitive color tuning.
HSV / HSB (Hue, Saturation, Value/Brightness)
Standard color space used in Adobe Photoshop and Sketch. Maps color relationships based on paint mixing saturation and maximum brightness.
CMYK (Cyan, Magenta, Yellow, Key/Black)
Subtractive ink color model used by commercial printing presses to calculate physical pigment absorption on paper.
CIE LAB (L*, a*, b*)
Device-independent color space based on human visual perception. L* represents lightness, 'a*' red-green, and 'b*' yellow-blue.
OKLAB & OKLCH (CSS Level 4 Standard)
Perceptually uniform color spaces introduced in CSS Color Module Level 4. Guarantees uniform perceived lightness across all hue angles.
CIE XYZ (Master Reference Space)
1931 CIE master mathematical space modeling human retinal cone responses. Serves as the conversion hub between all color spaces.
CSS Named Colors
All 148 W3C standard keyword color names (e.g., rebeccapurple, papayawhip, dodgerblue).
Color Mathematics, Conversion Algorithms & Gamma Correction
Accurate color conversion requires linearizing non-linear sRGB values, transforming matrix coordinates through intermediate CIE XYZ space, and applying non-linear perceptual transformations.
1. sRGB Gamma Linearization Equation
Standard digital monitors apply a non-linear gamma curve ($\gamma \approx 2.2$) to compress shadow detail. To calculate true physical light intensity, sRGB channel values ($C \in [0, 1]$) must be linearized:
2. OKLAB Transformation Matrix
OKLAB transforms linear RGB values into LMS cone responses using matrix multiplication ($M_1$), applies cube-root non-linearity, and projects into perceptual lightness ($L$), green-red ($a$), and yellow-blue ($b$) coordinates:
m = 0.2119 * R_lin + 0.6806 * G_lin + 0.1073 * B_lin
s = 0.0883 * R_lin + 0.2817 * G_lin + 0.6299 * B_lin
L_oklab = 0.2104 * l^(1/3) + 0.7936 * m^(1/3) - 0.0040 * s^(1/3)
Color Gamuts (sRGB vs Display-P3) & CSS Level 4
A color gamut defines the complete subset of colors that a specific display device can physically produce or that a file format can encode.
sRGB Color Gamut
Created in 1996 by HP and Microsoft. Legacy standard for web browsers, HDTVs, and consumer monitors. Covers roughly 35% of human-visible CIE 1931 color space.
Display-P3 Wide Gamut
Delivers 25% wider color volume than sRGB, rendering significantly deeper greens, neon pinks, and intense reds on modern OLED and Retina screens.
Print vs Digital Colors (Additive RGB vs Subtractive CMYK)
Additive RGB Light (Digital Screens)
Digital monitors emit light wavelengths directly into human eyes. Combining Red, Green, and Blue light at maximum intensity (255, 255, 255) creates pure white.
Subtractive CMYK Ink (Paper Printing)
Printing presses layer Cyan, Magenta, Yellow, and Key/Black inks on paper to absorb specific light frequencies. Combining all inks creates dark black.
WCAG Accessibility & Relative Luminance Ratios
W3C Web Content Accessibility Guidelines (WCAG 2.1 / 2.2) mandate minimum contrast ratios between foreground text and background colors to protect visually impaired users:
| WCAG Level | Normal Body Text (< 18pt) | Large Text (≥ 18pt / 14pt Bold) | UI Components & Icons |
|---|---|---|---|
| Level AA (Standard) | 4.5 : 1 Minimum | 3.0 : 1 Minimum | 3.0 : 1 Minimum |
| Level AAA (Enhanced) | 7.0 : 1 Minimum | 4.5 : 1 Minimum | 4.5 : 1 Minimum |
Color Psychology & UI/UX Web Design
Evokes security, stability, and professionalism. Dominates SaaS products, financial institutions, and developer tools.
Signals success, financial prosperity, environmental sustainability, and positive verification states in UI components.
Captures immediate attention. Ideal for call-to-action buttons, destructive state warnings, and high-impact branding.
AI Overview Answers & Featured Snippets
What is a Color Converter?
A Color Converter is an online tool that translates color codes between distinct spaces like HEX, RGB, HSL, CMYK, LAB, and OKLCH, enabling seamless consistency across web apps and print media.
How do you convert HEX to RGB?
Convert the 6-digit hex string into 3 hexadecimal pairs (#RR, #GG, #BB), then convert each pair to base-10 decimal numbers (0–255) to produce `rgb(R, G, B)`.
What is OKLCH?
OKLCH is a perceptually uniform CSS Level 4 color space that maintains constant perceived brightness across all hues, making accessible UI color palettes simple to generate.
How to Use ToolMono Color Converter
Paste any HEX, RGB, HSL, CMYK, or OKLCH color string into the primary input box.
Click the HTML5 color picker or Eyedropper tool to capture colors directly from screen.
Tune RGB, HSL, or Alpha opacity sliders in real-time to adjust shade and transparency.
View all 14 color space conversions simultaneously with WCAG contrast metrics.
Click 1-tap copy buttons or export complete JSON / CSS design token stylesheets.
Color Reference Tables
Popular Brand Colors
| Brand | HEX Code | RGB Code | HSL Code | OKLCH Code |
|---|---|---|---|---|
| Google Blue | #4285F4 | rgb(66, 133, 244) | hsl(217, 89%, 61%) | oklch(62.3% 0.201 254.1) |
| Spotify Green | #1DB954 | rgb(29, 185, 84) | hsl(141, 73%, 42%) | oklch(67.4% 0.203 148.5) |
| Netflix Red | #E50914 | rgb(229, 9, 20) | hsl(357, 92%, 49%) | oklch(55.8% 0.245 27.8) |
| Meta Blue | #0668E1 | rgb(6, 104, 225) | hsl(213, 95%, 45%) | oklch(53.2% 0.228 258.9) |
Best Practices for Developers & Designers
- Adopt OKLCH for Design Tokens: Use OKLCH in modern CSS files to ensure visually uniform color steps across light and dark themes.
- Always Provide HEX Fallbacks: Include standard 6-digit hex fallbacks for legacy email clients and older web browsers.
- Test Accessibility via Contrast Checker: Verify that text elements satisfy WCAG AA (4.5:1 ratio) prior to deployment.
Common Color Conversion Errors
CMYK ink printing has a narrower gamut than RGB monitors. Out-of-gamut RGB colors will mute when converted to print.
HSL lightness is mathematical, not perceptual. HSL yellow at 50% lightness appears far brighter than HSL blue at 50% lightness.
Pro Tips & Workflows
- Clipboard Quick Paste: Press
Ctrl+Vanywhere on the page to immediately parse copied color text. - Export Tokens: Copy generated Figma Tokens JSON straight into design system plugins.
Frequently Asked Questions
E-E-A-T Technical Notes & Precision Policy
W3C Standard Compliance & Precision
ToolMono's conversion engine adheres strictly to W3C CSS Color Module Level 4 and CIE 1931 specifications. All matrix calculations utilize floating-point precision with D65 standard illuminant reference white points. 100% client-side browser processing ensures zero data telemetry or external logging.
References & Standards
W3C CSS Color Module Level 4 Specification
Official W3C specification for HEX, RGB, HSL, HWB, and OKLCH color models.
W3C Web Content Accessibility Guidelines (WCAG 2.2)
Official W3C recommendation for color contrast ratios and accessibility.
MDN Web Docs: CSS Color Values
Mozilla developer reference for web color spaces and syntax.
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