JSON includes full metadata, per-dye parameters, and per-wavelength data. CSV exports all dyes. PNG captures the spectrum chart.
Beer–Lambert Law (ISO 7887, ASTM E169)
ISO 7887:2011 — Water quality — Examination and determination of colour. Specifies Beer–Lambert-based spectrophotometric methods for measuring colour of water samples with dissolved dyes.
ASTM E169-16 — Standard practices for general techniques of UV-Vis spectrophotometry. Covers absorbance measurement, cell path length, stray light, and wavelength accuracy.
Fundamental relation: A = ε · c · l, where A is absorbance, ε is molar absorptivity (L·mol−1·cm−1), c is concentration (mol·L−1), and l is path length (cm).
Kubelka–Munk Theory (ISO 18314)
ISO 18314-1:2015 — Analytical colorimetry of paints and coatings. Part 1 uses Kubelka–Munk theory to relate reflectance of opaque substrates to absorption (K) and scattering (S) coefficients.
K/S = (1 − R∞)² / (2 R∞). Additivity of K/S for multiple colorants enables linear dye recipe formulation on opaque substrates (textiles, paper, coatings).
Applicable when substrate thickness > opacity limit. For translucent layers, use generalised multi-flux models.
GHS & Chemical Safety (GHS Rev.10, OSHA HCS)
GHS Rev. 10 (2023) — Globally Harmonized System of Classification and Labelling of Chemicals. Defines hazard categories, signal words, pictograms, and safety data sheet (SDS) requirements for all chemical substances including industrial dyes.
OSHA 29 CFR 1910.1200 — Hazard Communication Standard (HCS) aligned with GHS. Requires employers to classify chemicals, maintain SDS, and ensure PPE availability.
REACH Annex II (EU) — Requirements for Safety Data Sheets including exposure scenarios for industrial dye usage.
Textile Dye Standards (ISO 105, AATCC)
ISO 105-C06:2010 — Colourfastness to domestic and commercial laundering. Defines standard washing conditions and grading scales for dye permanence.
ISO 105-B02:2014 — Colourfastness to artificial light (Xenon arc). Standard for assessing lightfastness of textile dyes.
AATCC TM 61 — Accelerated laundering test for evaluating dye fixation and fastness properties.
ISO 14184-1 — Determination of formaldehyde content in textiles. Relevant for reactive dyes that may release formaldehyde during fixation.
CIE Colorimetry Standards
CIE 015:2018 — Colorimetry, 4th edition. Defines standard illuminants, standard observers, XYZ tristimulus computation, and Lab* colour space.
CIE 142:2001 — Improvement to industrial colour-difference evaluation. Specifies CIEDE2000 formula for comparing dye batch colour consistency.
CIE 1931 2° observer colour matching functions (x̄, ȳ, z̄) used in this tool for spectral-to-XYZ conversion.
Environmental & Wastewater Standards
ISO 7887:2011 — Water quality colour measurement for effluent monitoring of textile dyehouses.
EU Water Framework Directive 2000/60/EC — Environmental quality standards for priority substances including certain azo dyes.
ZDHC MRSL v3.1 — Zero Discharge of Hazardous Chemicals Manufacturing Restricted Substances List for textile, leather, and footwear industries.
Beer–Lambert–Bouguer Law
A = absorbance (dimensionless, log10 scale)
ε(λ) = molar absorptivity (L·mol−1·cm−1)
c = concentration (mol·L−1), l = path length (cm)
Transmittance: T(λ) = 10−A(λ) %T = T × 100
Mixture: A_total(λ) = Σi εi(λ) · ci · l
Gaussian Band Model
λ0 = peak wavelength, σ = bandwidth (std dev, nm)
Temperature broadening: σT = σ × (1 + 0.003 · max(0, T − 25))
Kubelka–Munk Two-Flux Model
R∞ = reflectance of infinitely thick layer
K = absorption coefficient (m−1), S = scattering coefficient (m−1)
Additivity: (K/S)mix = (K/S)substrate + Σ ci · (K/S)i
Inverse: R∞ = 1 + K/S − √((K/S)² + 2K/S)
pH & Henderson–Hasselbalch Spectral Shift
For pH-sensitive dyes: ratio = 1 / (1 + 10(pKa − pH))
Δλ = pHShift × (ratio − 0.5) × 2
λeff = λ0 + Δλ
Temperature broadening: σT = σ0 × (1 + 0.003 × ΔT)
CIE XYZ Tristimulus Integration
Y = k · ∫ T(λ) · ȳ(λ) dλ
Z = k · ∫ T(λ) · z̄(λ) dλ
k = 1 / ∫ ȳ(λ) dλ Chromaticity: x = X/(X+Y+Z), y = Y/(X+Y+Z)
CIELAB: L* = 116 f(Y/Yn) − 16
a* = 500[f(X/Xn) − f(Y/Yn)], b* = 200[f(Y/Yn) − f(Z/Zn)]
f(t) = t1/3 if t > (6/29)³, else (29/6)²/3 · t + 4/29
Discrete Fourier Transform of Spectral Data
|F(f)| = √(Re² + Im²)
Peak frequency → dominant spectral periodicity.
Spatial frequency (cycles/µm) = f_peak / (N · Δλ)
XYZ → sRGB (IEC 61966-2-1)
G = −0.9689 X + 1.8758 Y + 0.0415 Z
B = 0.0557 X − 0.2040 Y + 1.0570 Z
EOTF: c ≤ 0.0031308 → 12.92c, else 1.055 c1/2.4 − 0.055
Clamp [0, 1] before quantising to 8-bit.
Spectrophotometry & Beer–Lambert
[2] ASTM E169-16 — Standard practices for general techniques of UV-Vis spectrophotometry.
[3] Lambert, J.H. (1760) — Photometria (original path-length law).
[4] Beer, A. (1852) — Bestimmung der Absorption des rothen Lichts. Annalen der Physik, 162(5), 78–88.
Kubelka–Munk Theory
[6] Kubelka, P. & Munk, F. (1931) — Ein Beitrag zur Optik der Farbanstriche. Zeitschrift für technische Physik, 12, 593–601.
[7] Nobbs, J.H. (1985) — Kubelka–Munk theory and the prediction of reflectance. Review of Progress in Coloration, 15(1), 66–75.
GHS & Chemical Safety
[9] OSHA 29 CFR 1910.1200 — Hazard Communication Standard (HCS), aligned with GHS.
[10] REACH Annex II (EU) — Safety Data Sheet requirements for industrial chemicals.
[11] ZDHC MRSL v3.1 — Manufacturing Restricted Substances List for textiles, leather, footwear.
Textile Dye Standards
[13] ISO 105-B02:2014 — Colourfastness to artificial light (Xenon arc).
[14] AATCC TM 61 — Accelerated laundering test for dye fixation and fastness.
[15] ISO 14184-1 — Determination of formaldehyde in textiles (reactive dyes).
CIE Colorimetry
[17] CIE 142:2001 — Improvement to industrial colour-difference evaluation (CIEDE2000).
[18] Smith, T. & Guild, J. (1931) — The C.I.E. colorimetric standards. Transactions of the Optical Society, 33(3), 73–134.
DFT & Signal Processing
[20] Bracewell, R.N. (2000) — The Fourier Transform and Its Applications (3rd ed.). McGraw-Hill.
About this tool
This tool implements Beer–Lambert spectral mixing, Kubelka–Munk K/S opaque substrate modelling, pH titration, CIE 1931 chromaticity, CIELAB colorimetry, DFT spectral decomposition, GHS hazard assessment, PPE compliance gating, batch analysis, and bootstrap confidence intervals — entirely client-side (zero network). Not a substitute for certified laboratory measurement, professional safety assessment, or regulatory compliance review.
Advanced analysis tools for dye chemistry research. Render a spectrum in the Lab tab first.
Non-parametric bootstrap (Wichmann & Hill, 2001 approach): resamples the rendered spectrum B times, plots the distribution of peak-absorbance estimates. 95% CI = [2.5th, 97.5th] percentiles of bootstrap distribution.
Paste an exported JSON array of dye sessions to compare multiple recipes: mean absorbance, CIE chromaticity, dominant wavelength, and Lab* metrics across batches.