The Ins and Outs of PC Audio Jack Colors. In many cards, the microphone connector will be pink, the line out or headphone will. be lime green, and the stereo line in will be light blue. Additional jacks may be present. on newer soundcards for rear and mid surround speakers. There is a widely accepted color standard for computer sound card input and output.
If one of the key features of Wi-Fi calling is that you can start/receive a call while on Wi-Fi and it will hand off to the cell network in a seamless fashion, that might not be true for some iPhone 5 users on T-Mobile.
So, as long as you have a network connection, you can make a call. If you can, though, connect your iPhone to a Wi-Fi network before using FaceTime. Video chats use a lot of data and using Wi-Fi won't eat up your monthly data limit. Once those requirements are met, there are two ways to FaceTime someone.