Stack overflow on finite recursion

I tried to make an algorithm to fill all tiles adjacent to each other with the same color, but when I run it it throws the Exception.

This is the code:

 function Colorear(naciones:Transform[],colores:Color[],n:int,color:Color){
     if(colores[n].a==0){
         colores[n]=color;
         for(var nacion_vecina:Transform in naciones[n].GetComponent(nation1).locacion.GetComponent(ubicacion).Conexiones){
             var lugar=System.Array.IndexOf(naciones,nacion_vecina.GetComponent(nation_helper1).nation);
             if(nacion_vecina.GetComponent(nation_helper1).nation!=null){
                 if(nacion_vecina.GetComponent(nation_helper1).nation.GetComponent(nation1).colornacion==naciones[n].GetComponent(nation1).colornacion && colores[lugar].a==0){
                     Colorear(naciones,colores,lugar,colores[n]);
                 }
             }
                 
         }
     }
     
 }

Since the amount of nations is finite, and this code colors them each time it's called before making the recursion, it should eventually end (they are only a few hundred nations), and yet it crashes.