I’m doing a scarf --maybe all in seed stitch (knit flat), I haven’t quite decided yet. But it definitely will have horizontal stripes. Usually I do a chain edge (slipping the first stitch of each row) to avoid messy edges, but how would I do that when it’s time to change colors? I’ve only really changed colors while knitting in the round, so am confused about doing it at the adge of flat work. Especially when I factor in the issue of the messy edges!
You could always change colours on the last stitch of the row below the new colour - that way you should still be able to slip the first stitch on the next row.
I would leave out the slipped stitch at beginning of the row and just carry yarn up side, catching/twisting at sides when not changing colors.
I’ve never done the slip st. edges, can’t see any advantage to it and often its a nuisance & haven’t noticed any messy edges.