I'm very happy to be learning all about the possibilities of my "not exactly typical blue and with dirty white layers" 7L chevron.

Since other similar beads are out there, it looks like the best hypothesis is yours - that poorer quality, contaminated, and/or waste glass was used to make these chevrons, making the colors much less vivid than in the "typical" chevron production.

I appreciate all the responses on this bead - very educational!