When I did the headliner on my 70 Challenger, the bows were NOT colour coded... They were all red on the ends.
I fortunately had the opportunity to number mine as they came out, so I put them back in the same way.
However, everything that I have read says that some of the bows can be swapped. But, it is not recommended with used bows as they typically have formed to the position they were in for the last 30+ years. If your bows are used you may just want to install them without a headliner and try to see where they seem to fit the best.
Also, when you do eventually install the headliner don't forget that the last bow closest to the rear window typically has two small wires that hook around the bow and clip into the actual roof of the car just above the rear window. These are used to pull the headliner back and help to keep it taut from front to back.
Also, *clean everything*, and use lots of spray adhesive along the sides where there are no "teeth" to hold the material. You will be glad you did when your headliner turns out wrinkle free.
