A little trick for color knitting in the round.

To smooth the step from color change, I used a simple method: in the last row of the current color, I knitted the last stitch of the row together with the stitch of the previous row (the lower one).
Here you can assess how noticeable the seam of the rows-stripes is:

Let's assume that the stitch marked in black is the last stitch of the current color (it is also the last stitch on the needle, the next needle starts with a new color)

Usually, it is simply knitted and that creates the very step.
So, you need to knit not that stitch, but the one below it, marked in black in the next picture.

In doing so, there is no need to specially unravel the upper stitch; just insert the needle into the lower stitch (the stitch becomes somewhat double, the lower stitch and the thread lying on it from the upper one) and knit.