This video teaches the secret to change the color at the end of a crochet row. An excellent summary is given below. First do the last double crochet by wrapping around, stick it through your last Stitch, wrap around again, pull through and stop. Grab the second color, leave a little bit of tail, put it on your hook and pull through all the loops. Grab your new color leaving the tail, wrap around and pull through for chain 1, again do the same for chain two and turn it around. To continue...