Are all artificial food colorings azo dyes?

No, not all artificial food colorings are azo dyes. While many synthetic colorants used in food, such as Red 40 and Yellow 5, are indeed azo dyes, there are other categories of artificial colorings that do not fall under this classification. Examples include anthraquinones and other chemical structures. Therefore, artificial food colorings encompass a broader range of compounds beyond just azo dyes.