This is SVG for circle with colors green stroke and fill (no use of CSS):
<?xml version="1.0" standalone="no"?>
<!-- Created with Sketsa SVG Editor (
http://www.kiyut.com) -->
<svg contentScriptType="text/ecmascript" width="600.0px" xmlns:xlink="
http://www.w3.org/1999/xlink"
baseProfile="full" zoomAndPan="magnify" contentStyleType="text/css" height="600.0px"
preserveAspectRatio="xMidYMid meet" xmlns="
http://www.w3.org/2000/svg" version="1.0">
<ellipse rx="96.0" fill="#00cc00" ry="96.0" cx="312.0" cy="177.0" stroke="#006600"/>
</svg>
This SVG copied into text file renamed, say, circle.svg - file dragged onto (any) browser will display the circle.
Author Joeg says SVG maybe unworkable but 'old versions of IE' count for nothing. Inline SVG is the way to go for (mobile) apps with (interactive) graphics - Maybe see
webapps.me.uk/bg.html that has page on SVG with BlueGriffon.
If necessary to use CSS, then maybe see 'How to Style SVG Using CSS' at
sitepoint.com/svg-styling-with-css/