True Grasscloth provides a unique décor opportunity of beautiful texture of natural fibers randomly assembled into wide sheets of wallcovering. The beauty is in the textured fiber not the overall matching ability. When applying dye to the fivers or straws, they do not all absorb the colors evenly. That is the beauty of it, natural fibers. Be wise and do not embark on a grasscloth project expecting the sheets to have a match. They do not, it is impossible.
When making attempts to obtain the best overall appearance, be sure to shuffle your rolls around before cutting the sheets. By doing this, you can possibly avoid some stark contrast between sheets. It will probably require having extra material on hand to work with and from. Or just accept it for what it actually is and enjoy the look.