Yes, I see it now. I couldn't remember my password so had to come on the computer instead of my iPad. Those are pretty!
Okay, I see... my previous post has the correct way to handle it. Drop the old yarn and pick up the new one underneath so it kind of holds the other yarn and it's not just dangling. It'll take several rows before you'll see how it works.
Now if you're concerned about a hole where you actually join the color... don't worry about it. You can take the tail and weave it in closing the hole when you're done.