There's this Knitting Teacher who always tells her Fair Isle workshop students to test out the yarn for any given project by scanning the skeins (or taking a picture) and then digitally turning the shot into black and white. She says that if you can't tell how many colors there are in the black and white shot, then they're too close tonally to be distinguishable in your finished piece.
This Knitting Teacher (who teaches all over the country, I might add) makes a point to say this in every workshop. She even has examples to show the students, proof that, yep, if the colors aren't markedly different in b/w, they won't be in real life either, and a whole lot of effort will be expended on not a lot of effect.
I wish I could remember that teacher's name. And even more so, I wish I would follow her damn advice.
Case in point...
I give you Arhelon, with the central motif done. 19000 sts (yeah, I did the calculation).
If you stand real close, you can see that the turtle has green feet, head and tail, and the fishies have green scales... as opposed to the blue shades of the water. But from any distance at all, they look close enough as to be identical. If I'd done the Scan Test before starting, I would have known this. As it was, I knew it well before finishing the piece, but I kept telling myself that the color difference would show up more, the more I got done.
I was wrong.
So I looked at Arhelon, and I contemplated it. And then I remembered this Knitting Teacher who sometimes shocks her students by whipping out a Sharpie to correct small errors in Fair Isle knitting. Sometimes the students are amused, sometimes they gasp in astonishment (and dismay), but always, they're surprised that it actually works.
I looked at Arhelon, and I looked at my Sharpies, and then I looked at both again some more, and then...
But next time, next time dammit, I'm going to do what that teacher said BEFORE I start the project.