The only change is the position of the :hover. You have to use the :hover pseudo element prior to ::-webkit-input-placeholder. Try this:
textarea:hover::-webkit-input-placeholder
{
color:#2278CE;
}
Question
Well, I'm tryin' to change the colour of a placeholder when hovering...
CSS
#principal form label textarea::-webkit-textarea-placeholder:hover {
color:#2278CE;
}
HTML
<textarea cols="93" rows="15" maxlength="1000" placeholder="Write here."></textarea>
I need to know if it's right, if it isn't, how to do.
Solution
The only change is the position of the :hover. You have to use the :hover pseudo element prior to ::-webkit-input-placeholder. Try this:
textarea:hover::-webkit-input-placeholder
{
color:#2278CE;
}