Colours are so familiar for us that we cannot help wondering why they can be so troublesome and enigmatic for Philosophers. They can be found in many central problems in the History of Philosophy: from Aristotle examples for exclusions by contrariety and problems for the Principle of Excluded Middle to the collapse of Wittgenstein´s early Philosophy; from the discussion on the nature of secondary qualities in Modern Philosophy to more recent puzzles in the Hard Problem of Consciousness; from natural candidates for the synthetic a priori to the refusal of a sharp distinction between shape and content in Aesthetics; from challenges for an exclusive disjunction between subjectivity and objectivity to technical efforts to precisely express some inevitable vagueness of our language. Furthermore, colours are a kind of favourite example for many central philosophical arguments, which are used systematically to support some theses and to give some counterexamples to refute many other theories. Colours spur us to philosophize. The discussion on the nature of colours resides indeed in the core of many classical philosophical disputes, such as between Locke and Leibniz, Newton and Goethe and between Wittgenstein and himself. They represent problems to theories of perception and for rule-following, challenges to classical logical principles, illustration for harmonic and holistic systems, motivation for phenomenological arguments and modal systems of incompatibility, common ground to the Gestalt tradition and puzzles for some central accounts in Philosophy of Mind. In this sense, this Colloquium will examine and discuss different and seminal ways in which colours matter for Philosophy. Our Colloquium shall advance several discussions in different areas of Contemporary Philosophy and represent a comprehensive platform for further researches and collaboration programs. It will offer a forum for philosophers to interact across old disciplinary boundaries. The talks thereby delivered will be published in a book named “How Colours Matter for Philosophy”. This volume will be an essential resource for anyone working in some central areas of contemporary philosophy, and the starting point for future research in this fascinating field. 

Scientific Committee: André Leclerc, Aparecida Montenegro, Cícero Barroso, Joelma Marques, Marcos Silva, Nuno Venturinha.