---
title: "Chroma · generative art"
description: "Black, taken apart. Generative art plate #29 by Theodore Vorillas, drawn live in your browser from its code."
url: "https://vorillaz.com/lab/chroma"
---

![](https://vorillaz.com/_astro/chroma.CxQ1IUXJ_Z2eno1x.webp)

fig. #29 · rendered live in your browser from the code below

# #29 chroma

Black, taken apart.

- date

  2026.10.05

- tags

  generative-art · javascript

One line of black ink, one strip of paper, a little water. Everything the black was hiding comes out, in order of patience.

## The band

```javascript title="chroma.js"
// the front eases in, then glides, slowing as the paper fills
const front = solvent + travel * (1 - (1 - t) ** 2.4);
const run = max(0, front - origin);

// each pigment rides a fixed fraction of the run, spreading as it goes
for (const { rf, spread, mass } of pigments) {
  const centre = origin + rf * run;
  const sigma = 1.6 + spread * sqrt(run) * 0.85;
  const c = (mass * 9 / sigma) * exp(-0.5 * ((u - centre) / sigma) ** 2);
  pixel = mix(pixel, pigment, c); // translucent layers on clear paper
}
```

## References

- [Paper chromatography](https://en.wikipedia.org/wiki/Paper_chromatography)