Wii component cable. i have got a wii & been told that u can get a sharper picture with the add on

Question

i have got a wii & been told that u can get a sharper picture with the add on lead. I have got this lead and having alot of trouble getting the wii to work with it. I have a samsung 40"lcd tv a week old i have tryed all the plugs on the side and back ,The best i can get is black and white.And no sound l am annoyed that wii is not hd but getting a better game picture is a bonus thanks wayne