Convert SVG colors to Black and white

convert.js

function convertColorsToTotalBlackAndWhite(svgString) {
  const BLACK_THRESHOLD = 128;
  const WHITE_THRESHOLD = 127;

  const convertColor = (color) => {
    if (color.toLowerCase() === 'none') {
      return color; // Leave "none" unchanged
    }

    const hexToDecimal = (hex) => parseInt(hex, 16);

    const [r, g, b] = [1, 3, 5].map((start) => hexToDecimal(color.substr(start, 2)));
    const brightness = (r * 299 + g * 587 + b * 114) / 1000;

    if (brightness >= BLACK_THRESHOLD) {
      return '#ffffff'; // Convert to total white
    } else {
      return '#000000'; // Convert to total black
    }
  };

  const updatedSvg = svgString.replace(/fill=["']([^"']+)["']/g, (match, color) => {
    const newColor = convertColor(color);
    return `fill="${newColor}"`;
  });

  return updatedSvg;
}