Hi,
I use CSS to change attributes of the "200x160px" class which gauge uses ( at least by default).
Make new ui_template node and put following CSS-styling in that. Tab setting of ui_template node should be same what gauge have.
For example:
<!DOCTYPE HTML>
<html>
<head>
<style>
[class="200x160px"] text {
font-size: 30px !important;
}
</style>
</head>
</html>
This changes gauge´s text font-size. Same approach works for any html element.
Best regards,
Juha