minhag - Stripes on a Talis

Is there any reason for the stripes on a talis? Does the color of the stripes have any significance?

Answer

From Rabbi Hershel Schachter's YUTorah lecture on the topic:

The stripes are reminiscent of the techeilet (blue string) that everyone used to wear; depending on the concentration of the dye, you could a color anywhere from light blue to near-black; hence some people have blue stripes, some have black.

I believe there are also kabbalistic meanings behind the stripes (try Rabbi Aryeh Kaplan's A Thread of Light), but the above is the simple explanation.