> Sure, color is an important tool at the disposal of a designer. But so are typography, layout, proportion, symmetry, hierarchy, contrast, and affordance. And those are just the static things! Designing good interactions additionally requires consideration of speed, motion, order, and timing.

Thats not what Flat UI is about , that's what graphic design is about.

Flat UI is a gimmick,and a fad. Non designers like it because there is nothing to it, anybody can make something look "Flat". It became an excuse for poor design skills, and pushing generic templates as design work.