The truth is we have very little information on what Romano-Gaul clothing was like. Certainly the standard dress for a class conscious woman would have consisted of a Tunica, a Stola and a Palla or Mantle for outdoor wear. It's not really until mid 2nd century that we begin to see depictions of Romano-Celts, both in Spain and Gaul, but the dress of the Plebeians is anybodies guess. While Romano-Gaul’s may have worn traditional Roman garments, materials and patterns/colours may have been quite different featuring more traditional checkerd and striped patterns as was the case in Britannia.
Remember, the dress was simple, not overstated see here: http://www.roman.org.uk/index2.htm
this dress is historically correct for 1st Century Britannia, these are the ladies of Legio VIII MGV in Britannia.
Billy's images are very interesting, but would be lower status dress, but it's all down to what social class, and in particular what period you want to dress for.