Chrome is more an attitude than a specific implant. It can be a fashion statement, or a mild form of cyberpsychosis. If you go for chrome, you refuse to hide your cyberware. You cannot have SkinGraft that makes you look normal, and your other systems are highlighted in chrome.
A variant of Chromehead is Crude; your cyberware is simply so primitive and/or cheap that it is easy to spot, with a metallic, industrial look