Changing Colors

I am knitting a dishcloth that have 2 colors. The directions state not to cut the yarn after using the colors. The colors start at the beginning of a row. How would I go about changing the colors. Margie:woohoo:

To start a new color just start knitting with it. You can weave in the end and fix any loose areas later. To use them bring the new color under the old one on the side which will twist them eventually so there are no loose edges.