Well, if you do your scarf in garter stitch instead of seed stitch, on the one hand you would need to do more rows to get the same size as the pattern, but on the other hand you'd have a fuzzier scarf in the end.
I agree the yarn is very hard to see, and I know I've made a lot of mistakes, but nobody's ever going to see them.
Anyhow, here's my scarf, with my 9-year-old daughter modeling it (well, it's hers now). :? It was knitted the long way in garter stitch, with one row on each stripe full of YOs and K2togs to make it wavy (and those were hard to keep track of!), and some fringe was added on the ends. And I used size 11 needles.