Snowbum's BMW Motorcycle Repair & Information Website

BMW used different colored dials, markings, pointers, and plastic colors of indicator lights, depending on model & year. There have been some anomalies, that may not agree with the below information.  See the NOTES section too.

This paragraph is for the /5.   The /5 had its instruments inside the metal headlight and wiring and ignition, and was very different from all the later Airheads.   The /5 headlight bucket contained the main electrical switch (which used the 'one size/type fits all' key, often called the Nail Key), and various function lamps, and the speedometer was a combined unit, with the smaller tachometer below.  Lamps were BA7 and BA9 types.  The indicator lamp colors (lamp jewel colors) were:
GEN:   Red, in a BA9 insulated socket.
High beam:  Blue.
Neutral:  Amber or green, in a BA7 insulated socket.
Oil:  Amber.
Turn:  Green or amber.
Parking:  white, in a BA9 insulated socket.
There was a two-terminal thermally operated turn signal flasher relay.
The instrument pointers were white, and the instrument markings are also white.
For the /5, see the following article, which covers the mechanicals, the lamps placement, removing the bezel, and a LOT more!
http://velobanjogent.blogspot.ca/2011/04/bmw-motometer-instruments-twin.html

The 1974 was the beginning of the /6 series and only the 1974 had white squares all around.
1974-1977 (/6 series and first /7) had the Hi beam indicating lamp at the bottom of the tachometer face.  Pointers are orange into mid-1977, and markings were in white.  In 1974 only there was a white surrounding area inside the rim edge.   While there was both a /6 and a /7 in 1977, the dial markings were white for all of them. The oil lamp was AMBER color, and the turn signal lamp was also AMBER, located at the bottom of the tachometer face.  The brake failure lamp is the top lamp in the center lamps group, then came the neutral lamp, GEN lamp, Oil lamp.
The /7 series had the turn lamp on the top, and just below it is the Oil lamp.  Neutral lamp is second from the bottom.  The bottom lamp is the Brake Failure lamp.  Dial markings are green, pointers are white.
1978 was the transition year for the electronic tachometer; and BMW changed the numbers and text from white to green, but a white pointer.
1981+ had a blue plastic lens for the high beam indicator lamp, and it was at the bottom.   The turn signal lamp was greenish, and located at the top.  The High beam lamp was blue and located at the bottom.  The instrument markings were green with white pointers. There was no brake failure lamp.  The OIL lamp is now RED.