input[type="color"] {
  -webkit-appearance: none;
  appearance: none;
  border: none;
  padding: 0;
  background: none;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 0; /* or whatever radius you want */
}