Problems with color

I’m making a deathly hallows wristband. But, when I try to do intarsia the yarn just pulls out. It started unraveling down the middle. I’m not exactly sure what I am doing wrong.

You need to make sure you are wrapping the yarn properly when knitting intarsia. Here’s a video.
http://www.knittinghelp.com/apps/flash/video_player/play/2/1