- white       VSS 
-s grey/pink  VSS sense (connect to VSS at encoder side)
+ brown       VCC
+s blue/red   VCC sense
A green       channel A
-
A yellow      should be *A or /A complement A
B grey        channel B
-
B pink        should be *B or /B complement B

O blue        rerefence pulse 
-
O red         compl. ref.
g black       shassis groung

John, look at the label to see the polarity of A, B and C signals. It seems as standard RS422 output if powered by 5V, otherwise it is again a push-pull driver, but look at the data sheet better.
The colors are different from those of Heidenhain, do net rely on them.
Best regards,
Fedia