@font-palette-values

@font-palette-values --identifier {
  font-family: Bixa;
}
.my-class {
  font-palette: --identifier;
}

<p>default colors</p>
<p class="alternate">alternate colors</p>

@import url(https://fonts.googleapis.com/css2?family=Bungee+Spice);
p {
  font-family: "Bungee Spice";
  font-size: 2rem;
}
@font-palette-values --Alternate {
  font-family: "Bungee Spice";
  override-colors:
    0 #00ffbb,
    1 #007744;
}
.alternate {
  font-palette: --Alternate;
}