It is not ready to wear quite yet but the cloth in the photo will be transformed for next fall. On the bottom is a 14 ounce Shetland jacketing in a dark and light brown herringbone with overchecks in navy and tan. It will go to Peter Harvey of London's Davies and Son in February to be made into an odd jacket.
Resting on the tweed is a swatch of a 13 ounce rust-colored gabardine that appears to bring out the tan overcheck. I'm going to see what that color looks like made up into trousers.
We often see cavalry twill or whipcord trousers with a tweed jacket and gabardine is in that same twill family. Jacket and trousers will be close enough in weight to be worn together and the tightly woven gabardine will add visual interest next to the roughness of the tweed.
Repeating a secondary color of a jacket in the trousers can make for harmonious combinations just as it does with shirts and neckties. The palette of rust, brown, tan and navy blue should provide plenty of opportunity to wear it with interesting shirts and neckwear.