Basis for coloring a dot matrix of 64 x 64 points.

SixtyFour.pde

import com.krab.lazy.*;

int cols = 64;
int rows = 64;
LazyGui gui;

void setup() {
  size(1280, 1280, P2D);
  gui = new LazyGui(this, new LazyGuiSettings().setLoadLatestSaveOnStartup(false));
  rectMode(CENTER);
  colorMode(HSB, 1, 1, 1, 1);
}

void draw() {
  background(gui.colorPicker("bg", color(0.1f)).hex);
  translate(width * 0.5f, height * 0.5f);
  int i = 0;
  for (int yi = 0; yi < rows; yi++) {
    for (int xi = 0; xi < cols; xi++) {
      cell(xi, yi, i++);
    }
  }
}

void cell(int xi, int yi, int i) {
  gui.pushFolder("cell");
  float xn = norm(xi, 0, cols-1);
  float yn = norm(yi, 0, rows-1);
  float in = norm(i, 0, cols * rows);
  float range = gui.slider("range", 1000);
  float x = -range * 0.5f + xn * range;
  float y = -range * 0.5f + yn * range;
  float size = gui.slider("size", 10);
  float theta = atan2(yi - rows / 2, xi - cols / 2);
  float thetaNorm = (PI + theta) / TAU;

  fill(color(1, 1, 1));
  noStroke();
  rect(x, y, size, size);
  gui.popFolder();
}