Default closable error notification

How to make notification Type.Error_Message closable by default without modifying each one with styles? I tried:

.v-Notification.error {
@include valo-notification-closable-style;
}

Which did trick, but close button (x in circle is dark black color instead of white as on Valo example page). How to make it look like on Valo Sample page?

Well :

.v-Notification.error {
@include valo-notification-closable-style;
&:after {
color: #FFF;
border-color: rgba(255, 255, 255, 0.3);
}
}

Did that trick.