.button {
   @include button($grey-15, $button-text-color); 
    
   &.blue      { @include button($blue, $white); }
   &.green     { @include button($green, $white); }
   &.orange    { @include button($orange, $white); }
   &.red       { @include button($red, $white); }
   &.black     { @include button($grey-90, $white); }
   &.white     { @include button($white, $text-color); }
}