Not any more!
Many of you suggested the Jogless Stripes tutorial at NeedleNoodles.com, so I tried it and BINGO!
No more stepping. (And it's so easy, too)
I began my jogless striping method from the yellow round (see arrow) downwards and look! Virtually seamless colour changes.
Genius, I tell you.
Thanks to all of you who made comments and suggestions- you peeps really make my day.
Xx