A lot of beginners learn how to knit by making scarves. The only problem with that is that single-colored scarves are really boring for you because you just have to knit on the same color forever. I'm going to show you how to use 2 colors to knit a simple stripe scarf.
I am using a garter stitch, which means knitting on the front and knitting on the back. I'm going to finish the row that I'm on here, with color Number 1; we're going to call this tan color, color Number 1. When it's time to knit with the second color, you're going to bring it up the side like this, and I'm going to slip the first stitch and put this yarn behind because I'm making a slip stitch edge. Then all you have to do to start knitting with color Number 2 is just wrap the new yarn around the needle with color Number 2. Whether this is your first row or your seventeenth row, all you have to do is wrap the yarn around.
If it's your first row, the yarn will be just loose, it won't be attached to your knitting yet, so trap it with your fingers behind there and pretend like it is coming from your knitting, leaving a tail. As you can see, I've let a little tail down here so that you can weave those ends in later. Then you're just going to start knitting with color Number 2. The only thing about this is that when you're knitting on the front, it's a really beautiful, simple edge that you have between color Number 1 and color Number 2. As you'll see when we turn it onto the back, knit stitches in 2 different colors do something funky. Or rather, when you are knitting on to Color 1 with Color 2, you get something on the back, that you could use as a design element.
See how the color is divided up here? You could decide that that looks really cool, and use it that way, or you could just say, "That's the back or the inside of whatever I'm knitting." With a scarf, though, you don't have an inside. People will see the wrong side, so you get to choose how you feel that look.
I'm going to complete my row. This is the backside. I slipped my first stitch, and I'm just knitting straight across. Any beginner could make this simple garter stitch scarf with 2 colors. Like I said, there is a wrong side, which is not very desirable for a scarf. I'm going to finish this row then I'm going to show you what it looks like in Knit 1 Purl 1, which is a neat trick for hiding your color changes.
Here we go. I finished that row. There we have the row of color Number B. We have an end hanging out here of Color A. We've just finished with Color B, so I'm going to prepare the next row by slipping the first stitch, sticking the yarn behind, and then I would just start using Color A like I did with color B. That's how to do a simple 2-row stripe. Of course if you want your stripes to be taller, you're going to have to keep that yarn handy and not forget that it's hanging down there. I wouldn't make your stripes too big, because then you'll have these big floats of color being brought up the side.
Here is a little sample of a Knit 1 Purl 1, and I did do slightly taller rows here. If you pull these apart, you can see the purl gutters here, and that is where the color-change happens, so you don't really ever get that wrong side. If you're going to do a scarf that is 2 different colors, I will say make it in a Knit 1 Purl 1 rib. That way you just get clean, even color breaks on both sides.
Here is an example of a scarf knit in a Knit 1 Purl 1 rib, with yarns that change colors as they go. A color-changing yarn, striped with a different color-changing yarn gives you a really, really neat effect. That is how to knit a striped scarf.