Welcome steamman. You'll find the topic of variegated
horn-button centres provokes quite a bit of controversy around here. There was
a thread on the topic only recently.
The long and the short of it appears to be:
- blue was the standard and most common colour of horn buttons for both FE and FC.
- aged horn-buttons can appear to have a gold centre, but most often this is due to the original blue colour fading out
- small numbers of horn-buttons appear to have been produced with green/violet/gold and brown centres rather than blue. They aren't recorded as parts with trim-codes in their own right, and they are extremely rare, so whether they were deliberately manufactured like that (perhaps as samples) or were accidents due to variations in dyes and processing is unknown.
Hope that's some help, (and doesn't fan those flames again
)
cheers
RET