Waypoint references a number of standard CSS class names. The following CSS code shows each of them along with recommended settings for each. 
Errors
/* ERRORS */
.WPERR_Error, .WPERR_Validation, .WPERR_Information, .WPERR_Warning, .WPERR_Fatal, .WPERR_Login, .WPERR_Success
{
	color: #000000;
	font-weight: 700;
	text-transform:none;
	background-color: #fdfadb;
	background-repeat: no-repeat;
	background-position: left;
	padding: 12px 7px 12px 42px;
	border:1px solid #808fb0;
	margin: 7px;
	display:block; /* adding to fix save button overlap.  */
}
.WPERR_Error, .WPERR_Validation, .WPERR_Fatal, .WPERR_Login, .WPERR_Information{ background-image:url(/wp-admin/images/ico-error.gif); }
.WPERR_Warning { background-image:url(/wp-admin/images/ico-warning.gif); }
.WPERR_Information { background-image:url(/wp-admin/images/ico-info.gif); }
.WPERR_Success { background-image:url(/wp-admin/images/ico-check.png); }
.err, .error{ font-weight: bold; color: Red;}