Do Fordyce Spots Turn Black In The Middle When They Are Frozen?

Hi,

I am a healthy 26 year old male. I recently found two spots on the shaft of my penis that were small and round. The doctor could not diagnose the spots because of the size but froze them anyway. The spots were present and frozen in a similar place 4 years ago. Do you think it could be enlarged Fordyce Spots? I do have fordyce spots on the underside of my penis (diagnosed by a doctor) but the two spots seem slightly larger. Do fordyce spots turn black in the middle when they are frozen?