page_colors.js

// Paste this into the console

var colors = [...document.querySelectorAll("*")].flatMap((el) => {
  const style = getComputedStyle(el);
  return [
    style.getPropertyValue("color"),
    style.getPropertyValue("background-color"),
  ];
});

[...new Set(colors)].forEach((color) => {
  console.log(
    `%c.%c${color}`,
    `padding: 0 30px; background: ${color}; color: transparent;`,
    `padding-left: 15px; background: transparent; color: unset;`
  );
});