During DNA sequencing, if all the bands on an electrophoresis gel are the same color, the single-stranded DNA sample consisted of one kind of fragment.

False!

A gel electrophoresis is used for separation of DNA (or RNA or proteins) or its fragments based on either size or charge. An electrophoresis gel can be stained in different ways. Whatever the staining is chosen, all of the fragments will glow the same color no matter what is the kind of fragments.