A document editing system supports globally editing the tone of an entire Web page without individually working on a plurality of factors characterizing the general effect (tone) of a document file such as a Web page. Upon receipt of an input of an effect (tone) from a user, parameterization occurs for a style tone of a style of a document file, a vector tone of a vector image included in the document file and a raster tone of a raster image included in the document file. A style adjuster then adjusts the style tone, the vector tone and the raster tone in response to the tone input from the user, and a display device displays the document file including the adjusted vector image and the raster image and modified according to the adjusted style.