The green side is clear for soft notes that will speak immediately with plenty of bottom and fundamental.  The white German felt soft side is designed for louder playing without any contact sound but still clean and free of contact noise.  As an orchestral player you will find this mallet a necessity in large orchestras for loud heavy works like Pictures at an Exhibition, Alexander Nevsky and Prokofiev 5 to name a few.  This mallet is also gaining strength and popularity among front ensemble players on the field.