Check out example codes for "placeholder color in css". It will help you in understanding the concepts better.

Code Example 1

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*/
}

Code Example 2

::placeholder

Code Example 3

<input type="text" placeholder="A red placeholder text..">

Code Example 4

/* do not group these rules */
*::-webkit-input-placeholder {
    color: red;
}
*:-moz-placeholder {
    /* FF 4-18 */
    color: red;
    opacity: 1;
}
*::-moz-placeholder {
    /* FF 19+ */
    color: red;
    opacity: 1;
}
*:-ms-input-placeholder {
    /* IE 10+ */
    color: red;
}
*::-ms-input-placeholder {
    /* Microsoft Edge */
    color: red;
}
*::placeholder {
    /* modern browser */
    color: red;
}

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