I think it's a great Harris Tweed! And my experience suggests it's harder to find things that won't harmonize, than will. (Though the people who dressed the model have come close.)
Slacks- Flannel, twill or cord, in any color that harmonizes with ground or any color in the tweed. Includes grey flannel, medium to charcoal, olive or tan cords, and twills also in olive and tan.
Shirts - white, blue, ecru to yellow, pastel green. Solids or pencil stripes.
Ties - Anything to...