Change element-UI button default style

Take warning as an example, just change or add the following styles

    /* Change element-UI button style */ 
  .el-button--warning { 
    color : #fff ; 
    background-color : #FC813B ; 
    border-color : #FC813B ;
  }
  .el-button--warning:hover{
    background-color: #EF9E6F;
    border-color: #EF9E6F;  
  }
  .el-button--warning:focus{
    background-color: #EF9E6F;
    border-color: #EF9E6F;  
  }