A three-dimensional ultrasound imaging system color user interface generates a volumetrically-rendered ultrasound image. The ultrasound image is manipulable using three-dimensional image compositing functions. The interface presents to the user three-dimensional image controls for controlling the ultrasound image. The three-dimensional image controls have an operational similarity to two-dimensional image controls for controlling a two-dimensional ultrasound image. The interface further relates the three-dimensional ultrasound image controls to the plurality of three-dimensional image compositing functions for manipulating the ultrasound images. Additionally, the interface presents to the user a three-dimensional color image control for controllably manipulating the ultrasound image using three-dimensional image using compositing functions such as a color flow mapping function, a color flow overlay function for mapping fluid flow direction, a depth-based velocity visualization color mapping function; and an absolute velocity representation function for mapping absolute fluid flow velocity relating to said ultrasound object.