<!DOCTYPE html>
<style>
textarea.red::-webkit-input-placeholder {
    color: rgb(100, 0, 0);
}

.blue::placeholder {
    color: blue;
    font-weight: bold;
    font-size: 16px;
}

.blue {
    width: 135px;
    height: 30px;
}

.prefixed-unprefixed::-webkit-input-placeholder {
    color: red;
}
.prefixed-unprefixed::placeholder {
    color: blue;
}

.unprefixed-prefixed::placeholder {
    color: blue;
}
.unprefixed-prefixed::-webkit-input-placeholder {
    color: red;
}
</style>
This tests that you can set the placeholder text color.

<div>
Default style:
<textarea placeholder="default"></textarea>
<textarea disabled placeholder="default disabled"></textarea>
</div>

<div>
::-webkit-input-placeholder:
<textarea class="red" placeholder="text"></textarea>
<textarea class="red" disabled placeholder="disabled text"></textarea>
</div>

<div>
::placeholder:
<textarea class="blue" placeholder="text"></textarea>
<textarea class="blue" disabled placeholder="disabled text"></textarea>
</div>

<div>
Both:
<textarea class="prefixed-unprefixed" placeholder="unprefixed"></textarea>
<textarea class="unprefixed-prefixed" placeholder="prefixed"></textarea>
</div>