I just checked the STA database and the colors they use in the threadcount for the Dutch Friendship tartan are, "Midnight; Brown; Orange; Green; Olive Green; Mauve." Their graphic looks reasonably like the colors in pictures I have seen.

Of course if you want the colors to match the cloth, it's best to send her a sample of the cloth itself, or at least a reasonably accurate picture.

Also, have you considered that this tartan may be a restricted design? It would be best to contact the designers of the tartan before having anything produced in it without their permission.