The chapter argues that a motivation of middle Wittgenstein’s concern with phenomenology is his dissatisfaction with the content-neutral account of logical syntax provided in the Tractatus. His approaches to the problem of colour-exclusion throughout his development are elucidatory in this respect. In early Wittgenstein’s view, propositions like “This cannot be of two colours [uniformly and coincidently]” express logical impossibility and involve contradiction. In 1930 Schlick presents a mirror-image of that view. For Schlick, propositions like “This is of two colours [uniformly and coincidently]” would express logical necessity and would involve tautology; such propositions are thus not synthetic a priori truths and, according to Schlick, are inadequately regarded by phenomenologists as groundings of their approach. In order to show why both early Wittgenstein’s and Schlick’s views on colour-exclusion are inconclusive, I draw on Ramsey’s critical review of the Tractatus and on middle Wittgenstein’s article “Some Remarks on Logical Form”. In light of Wittgenstein’s article, I then clarify the rationale of his subsequent conception of phenomenology as a logic of content.