We argue that introspection reveals a ubiquitous aspect of conscious experience that hitherto has been largely unappreciated in philosophy of mind and in cognitive science: conscious appreciation of a large body of background information, and of the holistic relevance of this information to a cognitive task that is being consciously undertaken, without that information being represented by any conscious, occurrent, intentional mental state. We call this phenomenon chromatic illumination. We begin with a phenomenological case study, involving an experience of joke-understanding in which the conscious aspect of chromatic illumination is especially vivid. Then we offer an account of the prototypical causal role of conscious intentional states (mental states that consciously represent their intentional contents), and we offer a contrasting account of the somewhat different prototypical causal role of conscious chromatic-illumination features of conscious intentional states. Finally, we describe the specific kind of physical-to-mental supervenience situation that needs to obtain in order for a chromatically illuminated conscious intentional state to figure as a supervenient mental cause that exerts both kinds of prototypical, content-appropriate, reasons-guidance vis-a-vis one’s cognition and behavior.