I believe both are strong possibilities. Nilomis has a very good point when he brought up the consistency of the color. I can see a scenario where some dials came into Omega with the incorrect color and they got used, for whatever reason.
It's hard for me to visualize how this could happen it this was attributed to exposure of the sun. But with that said "steelerfan" point with the rolex 16550's is a very strong argument that it evolved over time and with assistance from the sun.
I think this makes it all the more interesting, searching for answers and getting a greater knowledge base.
Does anyone have any ideas as to the originality of the bracelet? It appears to be genuine Omega with 2 links on each side of the buckle are expansion links making a very nice comfortable fit. It is marked "No 13" inscribed in a circle and also marked "4 over 69". Can I assume that this stands for April 1969 which would be the date of manufacture?
Thank you for sharing your knowledge its greatly appreciated
john