Color, Color Gradient, and Curves can be dragged from the library dockers directly onto effects, or onto the appropriate color/gradient/curve box in the effect editor. They can also be dragged from the editor out onto other effects. If you are dropping them on the timeline, it can be dropped on a group of selected elements. If you have 5 Pulse effects selected, and drop a gradient on one of them, it will be applied to all of the selected ones. If an effect has more than one possible color or gradient and you drop one on it, you will be given a option to select which color to replace.