This report is a summary of dozens of reports by owners. The true ratio of bikes produced with one color or another may be different.
The first year of the /5 was 1970. Those headlight shells had no indicator lights.
In 1971 they came with either a green or orange light as a turn indicator light.
In 1972 most came with a green turn signal indicator light. A few came with orange.
In 1973 Most came with a orange/yellow turn indicator light. A few came with green.
I received this interesting report below.
My /5 was built in Oct. 1970 and registered as a 71. I bought the bike new from Abt in Chicago in July of 71. It had no indicator on the headlight bucket. A dealer in Pa installed a green indicator and said it was a factory upgrade. I watched them do it. Perry
I am not slightly surprised by this report. It was normal for BMW to use up the parts that were for the past year and not right for the current year. Since the part number for a headlight shell didn’t change with the year, the old shell with no indicator light would never be ordered or desired.