I did a bit of work over the last year dissecting "cherry amber" beads and found that all of them had clear or cloudy yellow interiors. Based on an admittedly limited sampling, my hypothesis is that a large majority of old phenolic beads that we now refer to as "cherry amber" started life as faux (yellow) amber. Oxidation reactions at the surface slowly turned the beads a distinctive dark burgundy color. This behavior of old phenolic resins has been documented by others, but I think I may be the first to use dissections of beads in order to show the thin outer dark layer and the original interior color(s).
Here are a couple of the beads I sectioned. My full report on the subject was recently published in The Bead Forum, and can be accessed on ResearchGate. I also show an almost black phenolic bead that has a translucent green interior.