/* @import url('http://example.com/example_style.css'); */

/***********************************************/
/* CSS @imports must be at the top of the file */
/* Add them above this section                 */
/***********************************************/

/*****************************************/
/* Start your style declarations here    */
/*****************************************/

.pwr-services-item__icon--whiter{
    filter: grayscale(100%) brightness(0) invert(100%);
}

<link rel="stylesheet" href="https://kit.fontawesome.com/2bfba7592d.css" crossorigin="anonymous">