Color Picker & Converter

Authoritative Source & Methodology

The color conversions in this tool are based on the standard mathematical formulas for the sRGB color space, as defined by the International Electrotechnical Commission (IEC 61966-2-1) and adopted by the World Wide Web Consortium (W3C) for use in HTML and CSS.

AuthoritativeDataSource: W3C CSS Color Module Level 4
Reference: Section 4: sRGB Colorspace
Date: 21 November 2024
Link: https://www.w3.org/TR/css-color-4/

All calculations strictly adhere to the established conversion algorithms between these color models.

The Formulas Explained

Understanding how color models relate is key to digital design. Here are the core formulas this calculator uses.

RGB to HSL (Hue, Saturation, Lightness)

This formula converts the Red, Green, and Blue model to a cylindrical model that is often more intuitive for human selection.

1. Normalize R, G, B values: $R' = R/255$, $G' = G/255$, $B' = B/255$
2. Find max and min values: $C_{\max} = \max(R', G', B')$, $C_{\min} = \min(R', G', B')$
3. Calculate Delta: $\Delta = C_{\max} - C_{\min}$
4. Calculate Lightness (L): $L = \frac{C_{\max} + C_{\min}}{2}$
5. Calculate Saturation (S): $$ S = \begin{cases} 0, & \text{if } \Delta = 0 \\ \frac{\Delta}{1 - |2L - 1|}, & \text{if } \Delta \ne 0 \end{cases} $$
6. Calculate Hue (H): $$ H = 60^\circ \times \begin{cases} \text{undefined}, & \text{if } \Delta = 0 \\ (\frac{G' - B'}{\Delta}) \mod 6, & \text{if } C_{\max} = R' \\ (\frac{B' - R'}{\Delta} + 2), & \text{if } C_{\max} = G' \\ (\frac{R' - G'}{\Delta} + 4), & \text{if } C_{\max} = B' \end{cases} $$

RGB to HSV (Hue, Saturation, Value)

HSV (or HSB for Brightness) is very similar to HSL but defines saturation and value differently.

1. Normalize R, G, B and find $C_{\max}$, $C_{\min}$, $\Delta$ (same as steps 1-3 above).
2. Calculate Value (V): $V = C_{\max}$
3. Calculate Saturation (S): $$ S = \begin{cases} 0, & \text{if } V = 0 \\ \frac{\Delta}{V}, & \text{if } V \ne 0 \end{cases} $$
4. Calculate Hue (H): (The formula is identical to the HSL Hue calculation).

Glossary of Color Models

• HEX (Hexadecimal): A six-digit (or eight-digit with alpha) code representing RGB values. It's the most common way to specify colors in HTML and CSS. Example: #FF0000 is pure red.
• RGB (Red, Green, Blue): An additive color model where red, green, and blue light are combined in various proportions to produce other colors. Each value ranges from 0 to 255.
• HSL (Hue, Saturation, Lightness): A cylindrical model. Hue is the angle on the color wheel (0-360). Saturation is the intensity (0-100%). Lightness is the amount of black or white (0% is black, 50% is pure color, 100% is white).
• HSV (Hue, Saturation, Value): Also cylindrical. Hue and Saturation are similar to HSL, but Value (or Brightness) defines the color's brightness from 0% (black) to 100% (pure color).
• CMYK (Cyan, Magenta, Yellow, Key): A subtractive color model used in color printing. It describes how much of each ink is needed to absorb light and create the desired color on a white background. Key (black) is added for depth and efficiency.

How It Works: A Step-by-Step Example

Let's find the color values for a specific shade of "corporate blue".

1. Input: A designer gives you an RGB value: R=29, G=113, B=184.
2. Action: You enter these values into the R, G, and B input fields above.
3. Calculation: The tool instantly processes these values. Using the formulas:
   • $C_{\max}$ becomes $184/255 = 0.722$
   • $C_{\min}$ becomes $29/255 = 0.114$
   • $\Delta$ becomes $0.608$
   • Lightness (L) is calculated as $(0.722 + 0.114) / 2 = 0.418$ (or 42%)
   • Saturation (S-HSL) is $\frac{0.608}{1 - |2(0.418) - 1|} = 0.73$ (or 73%)
   • Hue (H) is $60 \times (\frac{0.114 - 0.722}{0.608} + 4) \approx 203^\circ$
4. Result: The tool auto-populates all other fields. You can now copy the equivalent HEX code (#1D71B8) or HSL value (hsl(203, 73%, 42%)) for your CSS file.

Frequently Asked Questions (FAQ)