irregular polygonal background - triangle low poly pattern - fall autumn color yellow, orange, ochre, rusty red, k

acute art autumn autumnal background banner blank color colored colour crystal cubism design diamond empty fall fraction fractional fragment geometric geometrical geometry gradient grid illustration irregular low lowpoly mesh modern mosaic network ochre orange origami pattern poly polygon polygonal rectangle red rusty seasonal shape sharp structure tessellated tessellating tessellation trend trendy triangle triangular vector wallpaper warm yellow