1. A non-transitory machine readable medium having a computer program for adjusting color values of an image represented in a color space, the image comprising a set of pixels, each pixel comprising a set of color values, the computer program comprising sets of instructions for execution by at least one processing unit, the sets of instructions comprising: displaying a composite bump on a tonal adjustment graph that is defined along a particular color component of the color space, the composite bump generated by blending a plurality of bumps on the tonal adjustment graph; in response to receiving an input on a location on the tonal adjustment graph, creating a new bump based on the input and blending the new bump with the composite bump to create a modified composite bump; and adjusting the color values of the image based on the modified composite bump.