DullBrown™ is the mixing colour of millions of photographs combined, the most generic colour in photography. DullBrown™ is based on the analysis of the classic benchmarking dataset Imagenet, a large visual database designed for use in visual object recognition software research. Within the machine learning interpretation of images, the most generic colour found in the analysed images is removed to identify unique qualifiers in a single image, and to determine what sets out the image from the rest of the images within the dataset.