Step 1: Knit one round in the new color and have your working yarn in your preferred hand (I am a thrower, but if you knit continental, this will work just the same, just imagine the yarn in the left hand).
Step 2: With your right-hand needle pick up the loop from the stitch on the previous row. This loop will be in the "old" color.
Step 3: Place the loop from the previous row onto the left needle beside the next stitch.
You will now have two stitches next to each other, one of the old and one of the new color.
Step 4: Stick the needle through the two stitches knitwise.
Step 5: Draw the yarn through both of the stitches.
Step 6: Slide the two stitches off of the left-hand needle as you normally would after having k2tog.
You now would continue to work as you normally do, changing colors as you wish or as the pattern indicates. It should be noted that when attempting jogless rounds you should have a minimum of two rounds of each color for this to be effective.
This is what my finished sock looks like.
Though you can tell where the color was changed, it is definitly less obvious than if I would have just changed colors without taking the steps mentioned above.