When knitting in the round, we are in fact working spiral rows and a disgraceful jog appears at color changes. It can be avoided by working a jogless join. There are different methods but this one can be used in every round.
At the end of the rnd (the red loop is my EOR -end of round – marker), place last stitch in round back on the left needle.
Knit that st again with new colour (if working stranded knitting, it’s the color of the first stitch in next round)
Knit next round normally but knit last stitch in round (the one that was knitted twice) from the stitch below (with tip of right needle lift the stitch under onto left needle and k2tog – knit the two stitches together).
This method can be used in every single round. The color changes are almost invisible.
You will find this tutorial and all my other tutorials grouped on this page: Support and tutorials.