Yeah, I'm afraid they need to be properly identified. Either by using a multimeter, or by following traces on the PCB, if you can see them well enough.
It's important to identify power and signal ground - nearly all logic chips have power on these corners with one end identified by a cut-out, like this:
Referring to your picture (which is looking at the bottom of the PCB and shows a 40-pin chip), ground will be on the top-right and power on the bottom-left pins of that chip.
My guesses are... the trace from the ground pin looks like it might go to the brown wire, but I can't tell for sure from the pic. The red wire goes to pin 4 of the chip, so is probably one of clock or data, and it also has a resistor on the trace - I would expect the other end of that resistor to be +5V, and it goes to the yellow wire. The other traces go off the pic
But don't take my guesswork as fact!! For one thing, there's an extra wire. It won't need to be used, but you need to figure out which one is the extra one!
Finally, clock and data can be determined by trial and error, since no damage will occur if they are swapped over.
That said, 5 minutes with a multimeter testing the cable would be quickest!