semantic/src/themes/twitter/elements/button.overrides

/*******************************
           Overrides
*******************************/

.ui.primary.button {
  box-shadow:
    0px 0px 0px 1px #3B88C3 inset,
    0 2px 0 rgba(255, 255, 255, 0.15) inset
  ;
}
.ui.primary.button > .icon {
  color: #FFFFFF;
}