Tis done! Finished it last night and is now creating a vibrant splash of colour on the couch.
The bottom join was created by doing Row 1, then on Row 2 inserting the hook through the corresponding other end in a zipper-like join. In this picture, Row 2 of the pink row was joined to the foundation chain of the blue row. This seam was joined with right sides together, then turned inside out so the seam lays flat.
The side seams were joined by single crochet.
Combining multiple colours is not something I’m good at, so for me, this project was quite a challenge. I’m really happy with the result though. Joining the top and bottom was an awkward, cack-handed affair and I was surprised at how well it turned out – you really can’t tell where the join is. Yay!