As you knit in the round, instead stacking rows of knitting you actually are proceeding in a spiral fashion. When the two ends come together, it is not noticeable unless you are making a color change. To minimize the impact of the spiral effect, you can slip the first stitch purl wise before introducing the new color. Continue knitting with the new color, knitting the originally slipped stitch when you finish the round. This stretches the stitch and pulls the jog in line with the pattern.