i just purchased a set of grey colored brake pads for shimano V brakes..they work very good...positive stopping , easy to adjust....heres my question...with out reading the packaging i installed them on my bike and road off...the other day my friend saw the pads and said why did i purchase ceramic pads for a not ceramic rim...can these pads do any damage to my rims or what will happen if i leave them on....?? i really dont know if these pads are ceramic or not...but they are grey in color and work fine....help help

thanks

jim