@nicole @duane All sorted. Did up my own custom css tweak for it, looks good. FWIW:

div.tooltip, div.mod-wide, div.mod-error {
font-size: 11pt !important;
font-weight: 600 !important;
padding: 2px 5px;
font-family: Arial;
line-height: 1em;
background-color: #AAFFAA;
color: black;
border: solid 2px #7EBD7E;
}

Also couldn't figure out how to change the default "divider" color for headings. Did that in custom css as well. You can probably tell I get a bit OCD with this stuff.. 😄