Here's a comparison between different material of the same Ziriyab pick:
Black: kevlar - gives a well rounded and balanced tone
Green: polipropilene - warm sounding pick very smooth attack
Orange: Nylon - warm attack but bright release again very smooth across the strings
White: Acetalica - very bright and strong attack my personal favourite
Grey: vetro 30% bright attack a little bit warmer than the one in acetalica
Blue: the warmest of all very soft attack with treble roll off
