Crochet with 2 colors in the round

When you work with 2 colors in the round and you want to carry along both the threads, then you crochet around the thread you are not working with to carry it along. The last stitch you make with one color, wait with last pull through and pull through with the color of the following stitch. You can carry along a color by crocheting around it for as many stitches you want, then when it is time to change, you just use it in the last pull through and continue with that color and not crochet around the previous color.
Remember - when carrying along a color or more the fabric will become much thicker.