About

Color mixing in digital environments frequently suffers from interpolation errors. Standard naive averaging of RGB values fails to account for the non-linear nature of human vision and the physical behavior of light, resulting in desaturated, "muddy" mid-tones. This instrument resolves these discrepancies by providing two mathematically rigorous mixing models: Additive and Subtractive.

The Additive model simulates the behavior of emissive light (such as monitors or stage lighting). It utilizes Gamma Correction (γ = 2.2) to transform standard sRGB values into a linear color space before interpolation, preserving accurate luminance. The Subtractive model simulates physical pigments, inks, or filters (CMYK/RYB). Rather than simple averaging, it calculates the transmittance and absorbance of each layer using an approximation of the Beer-Lambert Law, effectively multiplying the spectral absorption profiles to predict the physical result of mixing dyes.

Formulas

For Additive Mixing, values are converted to linear space using a gamma exponent before computing the weighted average:

C_linear = ∑ (w_i × (C_i ÷ 255)^2.2)∑ w_i

C_mix = √C_linear^2.2 × 255

For Subtractive Mixing, the tool approximates density (absorbance) using a logarithmic scale per the Beer-Lambert principle:

A_i = −log₁₀(C_i ÷ 255)

A_mix = ∑ (w_i × A_i)∑ w_i

C_mix = 10^−A_mix × 255

Where C represents the individual RGB channels (Red, Green, Blue), w represents the weight (parts) of the color, and A represents optical absorbance.

Reference Data

Mixing Type	Color 1	Color 2	Theoretical Result	Physical Analogy
Additive (Light)	Red (255, 0, 0)	Green (0, 255, 0)	Yellow (255, 255, 0)	Overlapping RGB spotlights.
Additive (Light)	Red (255, 0, 0)	Cyan (0, 255, 255)	White (255, 255, 255)	Complementary wavelengths summing.
Subtractive (Paint)	Yellow (255, 255, 0)	Cyan (0, 255, 255)	Green (0, 255, 0)	Mixing standard CMY printer inks.
Subtractive (Paint)	Cyan (0, 255, 255)	Magenta (255, 0, 255)	Blue (0, 0, 255)	Absorbing Red and Green spectrums.
Subtractive (Paint)	Red (255, 0, 0)	Green (0, 255, 0)	Dark Brown / Black (16, 16, 0)	Opposite hues absorbing all light.
Subtractive (Paint)	Cyan, Magenta, Yellow	Equal Parts	Black (0, 0, 0)	Perfect theoretical CMY absorption.

Frequently Asked Questions

This highlights the difference between light emission and light absorption. In the Additive mode (light), Red and Green wavelengths combine to stimulate both the red and green cones in the human eye, which the brain interprets as Yellow. In the Subtractive mode (pigment/ink), a red pigment absorbs green light, and a green pigment absorbs red light. Mixed together, they absorb nearly the entire spectrum, reflecting very little light back to the eye, resulting in a dark muddy brown or black.

Digital images use sRGB, which applies a gamma compression curve to optimize data for human perception. If you perform a simple arithmetic average on sRGB values (e.g., mixing Red (255,0,0) and Green (0,255,0) as (127,127,0)), the result is mathematically incorrect relative to physical light intensity. The midpoint luminance drops, causing the resulting color to appear dark and desaturated. Converting to linear space via Gamma Correction before averaging solves this.

Real paint mixing relies on complex physics including scattering, refraction, and particle size (Kubelka-Munk theory), which varies heavily by specific chemical pigments. This tool uses a deterministic Multiplicative/Density approximation based on optical transmittance. It behaves identically to overlapping colored glass filters or transparent cyan/magenta/yellow printer inks. While highly accurate for dyes and light absorption, opaque oil or acrylic paints may behave slightly differently due to white base reflections.

A weight of zero effectively removes the color from the interpolation equation entirely. It contributes 0 parts to the total sum of weights, meaning its values and absorbance profiles are ignored.