I want to make another cardigan for winter. But before I do, I just need to make something fast, nice and simple.
This seems to be the best choice.

Using more than 6 colors to make it really colorful. And to destash. I also changed the sections a bit, but their lengths are the same.

I slipped the first stitch to get a nice edge.

When making stripes you can also get a nice edge:
Row 1 (RS): slip 1st stitch (C1), twist yarn strands, knit until the end in C2.
Row 2 (WS): knit until last st, ptbl (C2).
Row 3 (RS): slip 1st stitch (C2), twist yarn strands, knit until the end in C1.
Row 4 (WS): knit until last st, ptbl (C1).

This worked for me - at least this is what I remember doing :-).