@ustk Thanks, that's perfect. Now I have to understand how the arch works to which I will assign "textColor"
laf.registerFunction("drawRotarySlider", function(g, obj)
{
var a = obj.area;
// Draw the background ellipse
g.setColour(obj.bgColour);
g.fillEllipse(a);
// Draw the inner ellipse
g.setColour(obj.itemColour1);
g.fillEllipse([10, 10, a[2] - 20, a[3] - 20]);
// Calculate the rotation angle
var start = 0; // Starting at 0 radians
var end = 2 * Math.PI * obj.valueNormalized; // Ending at 2π radians for full rotation
g.rotate(end, [a[2] / 2, a[3] / 2]);
// Draw the needle
g.setColour(obj.itemColour2);
g.fillRect([a[2] / 2 - 8 / 2, 0, 8, 40]);
});