1. A color arrangement checking device comprising: a document storage storing a full-color document in which elements of each color are placed on a page; at least one processor which implements: an attribute detection unit detecting at least a color and a size of the elements for each page of the document; an occupancy ratio calculation unit adding up the size of the elements for the whole page by the color and outputting this as an occupancy ratio; a color arrangement checking unit determining whether or not at least one of brightness and saturation exceeds a predetermined color threshold value for each color of the elements; and an occupancy ratio checking unit determining whether or not the occupancy ratio by the color of the elements, which assume the color, of which at least one of the brightness and the saturation is determined to exceed the color threshold value, as an attribute, exceeds a predetermined occupancy threshold value; and a result output display outputting the elements which assume the color, of which the occupancy ratio is determined to exceed the occupancy threshold value, as the attribute, wherein the predetermined occupancy threshold value of the color of which the brightness is determined to exceed the color threshold value is different from that of the color of which the saturation is determined to exceed the color threshold value.