Hello, Most of the information I have on American Ft-17 show a camouflage similar to the French camouflage, if not exactly like it. A dark green or darker olive green, Brown, tan. In a disruptive pattern. Check out this http://www.landships.freeservers.com/ft17_walkaround.html
I have attached some color drawing you can find here on Landships, The Americans Ft-17’s would look relatively the same. I also have a article by Mr.Steve Zaloga, on building a American Ft-17 for a diorama. If you are interested I can email this to you, if it will help.
the book Treat em rough, the birth of the american tank corps." has good photos and discription of the american ft-17s and other good info on early US tank arm