Hello Angelo,

That is defined in the theme’s skin. You can find it in src/theme/radialprogress.js

Here are the relevant lines:

selection.selectAll(".vz-radial_progress-label")
            .style("fill",skin.label_color)
            .style("stroke-opacity",0)
            .style("font-size",viz.radius() *.25);  

You might find our article “Themes and Skins” helpful if you want to learn more about changing the appearance of the radial progress component.

– Tom