How do I change the text color while hovering over it?

I can easily change the highlight state and error state by clicking the gear to the right of "simulate error state," or "simulate highlight state."

My problem is the highlight color of transparency does not effect the PayPal widget. I'm using a black background and when the products in that widget are highlighted the white text cannot be seen.

I used this code but it still does not work on the widget:

.form-line-active {

background-color:transparent;

}

.form-line-error {

background:none repeat scroll 0 0;

}

I have injected CSS to make the color of the text white when the mouse is hovered over it.

.hover-product-item:hover{
  color:white!important;
}
.form-line-active {
    background-color : transparent;
    color:white!important;
}

Let us know how it goes.

Thanks.