Here it is...
theTextR = app.selection[0].parentStory.textStyleRanges;
try
{
app.activeDocument.colors.item("Overtracked").name;
}
catch (myError){
app.activeDocument.colors.add ({name:"Overtracked",space:ColorSpace.CMYK,colorValue:[15,100,100,0]});
}
var i=0;
while (i<theTextR.length)
{
if (theTextR.tracking <= -15 || theTextR.tracking >= 15)
{
while (i<theTextR.length && (theTextR.tracking <= -15 || theTextR.tracking >= 15))
{
theTextR.fillColor = "Overtracked";
i++;
}
} else
i++;
}
alert("The tracking value more than -15 and +15 is highlighted in Red color.");