When you have to change colors, pick up the first color again. Carry the thread to the left behind your work, leaving it a little loose, and continue knitting the stitches according to the chart.You will see how the two colors of yarn are interlaced on the wrong side of your work.
Turn your work and purl the next row, following the color changes in the pattern. For this example the strands from the color changes will be facing you. Continue working, changing colors as needed, taking care not to pull too tightly and remembering not to cut the yarn. If you are going to make your own design, we recommend making a chart first and to avoid knitting more than 4 stitches without changing colors, as this will create very long strands that can cause the fabric to pucker.