css style placeholder

input::-webkit-input-placeholder {/* Chrome/Opera/Safari/Edge */
	/*styles here*/
}

input::-ms-input-placeholder { /* Microsoft Edge */
   /*styles here*/
}

input:-ms-input-placeholder {/* IE 10+ */
	/*styles here*/
}

input::-moz-placeholder {/* Firefox 19+ */
	opacity: 1; /*Firefox by default has an opacity object that usually is ideal to reset so it matches webkit*/
	/*styles here*/
}

input:-moz-placeholder {/* Firefox 18- */
	opacity: 1; /*Firefox by default has an opacity object that usually is ideal to reset so it matches webkit*/
	/*styles here*/
}

input::placeholder {
	/*styles here*/
}

::-webkit-input-placeholder { /* Chrome/Opera/Safari */
  color: pink;
}
::-moz-placeholder { /* Firefox 19+ */
  color: pink;
}
:-ms-input-placeholder { /* IE 10+ */
  color: pink;
}
:-moz-placeholder { /* Firefox 18- */
  color: pink;
}

::-webkit-input-placeholder {color: pink;} /* Chrome/Opera/Safari */
::-moz-placeholder { color: pink;} /* Firefox 19+ */
:-ms-input-placeholder { color: pink;} /* IE 10+ */
:-moz-placeholder {color: pink;}  /* Firefox 18- */

<form action="/action_page.php">
	<label for="phone">Enter a phone number:</label>
    <input type="tel" id="phone" name="phone" placeholder="123-45-678" pattern="[0-9]{3}-[0-9]{2}-[0-9]{3}"><br><br>
 </form> 
 

::placeholder {
  /*styles here*/
}

:-ms-input-placeholder { /* Internet Explorer 10-11 */
  /*styles here*/
}