Charlotte’s Web anyone?

Just wondering if anyone who reads this has ever done a Koigu Charlotte’s Web. I’m starting to think ahead about a project for my MIL and thought she might like one. From the pictures I’ve seen, I know that you use 5 different colors, but the thing I haven’t been able to glean is how you switch between them. Is it an abrupt switch after a certain number of rows? Is there a series of fade rows where you knit with both colors for a while (and so do you have to knit double in the non-transition rows?)? Or do you alternate rows in a transition section? I’ve looked at dozens and dozens of Charlotte pictures online and I haven’t been able to figure it out.

If it is a nice fade, I thought my MIL might really like this done in a variety of purple hues. So maybe some Purple-ish KPPPM with some solid purple KPM mixed in. Or maybe just the whole thing in purple shades of KPM.