button {
  position: fixed;
  top: 1rem;
  left: 1rem;
  z-index: 100;
  font-size: 2rem;
  border: solid black 2px;
  padding: 0.5em 1em;
}

svg {
  height: 0;
  width: 0;
  padding: 0;
  margin: 0;
}

img.yellow-filter {
  filter: url("#yellow-filter");
}

img.cyan-filter {
  filter: url("#cyan-filter");
}

img.magenta-filter {
  filter: url("#magenta-filter");
}

img.test-filter {
  filter: url("#test-filter");
}

.grayscale img.yellow-filter {
  filter: url("#yellow-filter") grayscale(1);
}

.grayscale img.cyan-filter {
  filter: url("#cyan-filter") grayscale(1);
}

.grayscale img.magenta-filter {
  filter: url("#magenta-filter") grayscale(1);
}