The item number and batch number on the wallpaper are very important. They are mentioned on the front of the label. Only use wallpaper with the same batch number in the same space. If the batch number is the same, there is little risk of colour differences. Always check if the wallcovering must be reverse hung. This may depend on the batch number and will be stated, if necessary, on the label or the cellophane packaging on the wallpaper.
Read more about reverse hanging here.