The man in the photograph, Yukio Akamine, demonstrates one way to relate a pocket square, a necktie and a suit to each other.
The suit main color is brown, the tie ground is beige and the pocket square is half orange and half mustard. The colors do not match, they complementeach other. Notice how the orange in the pocket square is subtlety present in the suit’s and tie’s patterns. This brings all the individual pieces together.
Also, we must consider the texture of the fabrics, because we can create interest by contrasting textures. Mr. Akamine demonstrates this with a necktie and a pocket square that brings some sheen to the otherwise matte outfit.
And that’s one way to relate our suits to our neckties, hankies and vice versa.