It is all logical as the bike is from a german company.
we = weib = white.
br = braun = brown.
gn = grun = green.
ge = gelb = yellow.
gr = grau = grey.
ro = rosa = pink.
As I mentioned if any of them short against each other then your bike controller is history as a couple will carry voltage certainly the brown will and maybe one other.
Ok yes the display will supply power via the thumb unit when switched on, remove the bike battery so one can't accidently switch the display on whilst soldering the wires back. In fact tape up each wire separately just in case.