"Most, if not all, products currently sold under the name “French dressing” contain tomatoes or tomato-derived ingredients and have a characteristic red or reddish-orange color. They also tend to have a sweet taste. Consumers appear to expect these characteristics when purchasing products represented as French dressing. Thus, it appears that, since the establishment of the standard of identity, French dressing has become a narrower category of products than prescribed by the standard. These products maintain the above characteristics without a standard of identity specifically requiring them." Plus there are variations in fat (oil).
So basically, the Standard of Identity is not needed. "Therefore, after considering the petition and related information, through the proposed rule, we tentatively concluded that the standard of identity for French dressing no longer promotes honesty and fair dealing in the interest of consumers consistent with section 401 of the FD&C Act and proposed to revoke the standard of identity for French dressing. The preamble to the proposed rule also noted that the proposed revocation is consistent with section 6 of Executive Order 13563, “Improving Regulation and Regulatory Review” (January 18, 2011), which requires agencies to periodically conduct retrospective analyses of existing regulations to identify those “that might be outmoded, ineffective, insufficient, or excessively burdensome, and to modify, streamline, expand, or repeal them” accordingly."