The vectors \begin{align*} \vect{u}&=\colvector{2 + 3i\\4 - 2i\\1 + i\\1 + i} & \vect{v}&=\colvector{1 - i\\2 + 3i\\4 - 6i\\1} \end{align*} are orthogonal since \begin{align*} \innerproduct{\vect{u}}{\vect{v}} &=(2-3i)(1-i)+(4+2i)(2+3i)+(1-i)(4-6i)+(1-i)(1)\\ &=(-1-5i)+(2+16i)+(-2-10i)+(1-i)\\ &=0+0i. \end{align*}