The present invention provides a method for modifying the manner in which a themed computer user interface element is rendered. The method includes obtaining source data defining the rendering attributes of the user interface element. Parameters are then provided for modifying the source data. The source data is then modified in accordance with the parameters to produce transformed source data reflecting the desired rendering attributes for the user interface element. The transformed source data is stored on the computer to enable displaying the user interface element using the transformed source data. The user interface element may then be rendered to, for example, a computer monitor using the transformed source data. The parameters may, for example, direct modifications to the brightness, contrast, color, volume, or other attributes of the source data. The present invention further provides a novel method for creating a color-shifted image from a raster source image that may be associated with a user interface element.