Running out of yarn

Okay, I am a newbie and I just finished my first project, a bib. I am now making a baby blanket but I am not sure I will have enough yarn to finish, what do I do if I run out? I am doing it all in a lemon yellow color, not changing colors at all. Would I just do like I would if I WERE changing colors?

Here is a video on joining a new ball of yarn.