Hi there, I can't seem to figure this out googling. What is the difference between the Motorola H710 and H721 bluetooths besides one is black and one is silver ? One website says the only difference is the color and other websites use the names H710/H721 interchangeably. I went to Motorola's own website and can't find H721 even listed. Help! Is there any other difference between the color?
