I am planning to knit a baby blanket on a knitting board. The pattern I want to create is a white panel that has a yellow star in the center of a white square. I know how to change colors for a new row, but how do I change colors right in the middle of a row? There would be two color changes in the rows where the star pattern would begin (white to yellow to white). Is this possible? If so, then what method do I use? I have attached an image file with the pattern I want to try.