/cgl/ - Cosplay & EGL

What's the best way to go about adding a stripe to a pleated skirt? I know I have to add it after hemming and before pleating, but should I
A) cut the section I want a different color away from the skirt and replace it (with seam allowance) with the second color I want
or
B) top stitch the 2nd color on top of the first fabric. And if B, do I narrow hem the top and bottom of the stripe or fold it like bias tape. Or instead of the inside flaps meeting in the middle do I just fold it in like a half inch??