1. A method, comprising: performing, by a computer: receiving input initiating a non-uniform paint loading operation, wherein the non-uniform paint loading operation is distinct from operations that deposit paint; and subsequent to receiving the input initiating the non-uniform paint loading operation: receiving input indicating selection of a region of an image on a digital canvas comprising a non-uniform distribution of paint colors; and performing the non-uniform paint loading operation, wherein said performing comprises loading a virtual brush with virtual paint having a distribution of colors corresponding to the non-uniform distribution of paint colors in the selected region; wherein said loading comprises storing data in each of a plurality of cells of a brush model for the virtual brush representing a paint color in a respective portion of the selected region.