gconf-settings/skel/.local/share/gnome-shell/extensions/unitehardpixel.eu/themes/telinkrin/maximize-active.svg

<svg height="16" viewBox="0 0 4.2333333 4.2333332" width="16" xmlns="http://www.w3.org/2000/svg"><circle cx="2.116667" cy="2.11667" fill="#3a6674" r="2.116667"/></svg>