<p>old colors</p>
<p class="new">new colors</p>

@import url(https://fonts.googleapis.com/css2?family=Foldit:wght@700);
p {
  font-family: 'Foldit';
  font-size: 2rem;
}
@font-palette-values --New {
  font-family: 'Foldit';
  override-colors:
    0 gold,
    1 red;
}
.new {
  font-palette: --New;
}