.btn-primary {
  background: #4285F4; }
  .btn-primary:hover, .btn-primary:focus, .btn-primary:active {
    background-color: #5a95f5 !important; }
  .btn-primary.active {
    background-color: #0b51c5 !important; }

.btn-primary {
    background: $primary-color;
    &:hover,
    &:focus,
    &:active {
        background-color: lighten( $primary-color, 5%)!important;
    }
    &.active {
        background-color: darken( $primary-color, 20%)!important;
        @extend .z-depth-1-half;
    }
}

.btn-primary:hover {
    background-color: red !important;
}

<form role="search" method="get" " class="searchform form-inline my-2 my-lg-0" action="<?php echo home_url( '/' ); ?>">
        <input class="form-control mr-sm-2" type="search" id="s" name="s" value="" placeholder="<?php _e('Search for','sage'); ?>" />
        <button type="submit" class="btn btn-primary my-0" id="searchsubmit" ><i class="fa fa-search" aria-hidden="true"></i></button>
</form>