Colors are just the most vivid example. Smells and feelings are definitely part of consciousness - that is, part of the same phenomenal gestalt as color - so they are definitely on the same ontological level. A few comments up the thread, I talked about color as a three-dimensional property associated with visual regions. Smell is similarly a sensory quale embedded in a certain way in the overall multimodal sensory gestalt. Feelings are even harder to pin down, they seem to be a complex of bodily sensation, sensations called "moods" that aren't phenomenally associated with a body region, and even some element of willed intentionality. Alertness itself isn't a quale, it's a condition of hyperattentiveness, but it is possible to notice that you are attending intently to things, so alertness is a possible predicate of a reflective judgment made about oneself on the basis of phenomenal evidence. In other words, it's a conceptual posit made as part of a high-order intentional state.

These discussions are bringing back to me the days when I made a serious attempt to develop a phenomenological ontology. All the zeroth-order objects of an experience were supposed to be part of a "total instantaneous phenomenal state of affairs", and then you had high-order reflective judgments made on top of that, which themselves could become parts of higher-order judgments. Cognitive scientists and AI theorists do talk about intentionality, but only functionally, not phenomenologically. Even philosophers of consciousness sometimes hesitate to say that intentional states are part of consciousness - they're happier to focus on sensation, because it's so obvious, not just that it's there, but that you know it's there.

However, it's also clear, not only that we think, but that we know we are thinking - even if this awareness is partly mediated by a perceptual presentation to oneself of a stream of symbols encoding the thought, such as a subvocalization - and so I definitely say intentionality is part of consciousness, not just sensation. Another way to see this is to notice that we see things as something. There's a "semantics" to perception, the conceptual ingredient in the phenomenal gestalt. Therefore, it's not enough to characterize conscious states as simply a blob of sensory quale - colors varying across the visual field, other sense-data varying across the other sensory modalities. The whole thing is infused, even at the level of consciousness, with interpretation and conceptual content. How to express this properly - how to state accurately the ontology of this conceptual infusion into the phenomenal - is another delicate issue, though plenty has been written about it, for example in Kant and Husserl.

So everything that is a part of experience is part of the problem. Experiences have structure (for example, the planar structure of a depthless visual field), concepts have logical structure and conditions of application, thoughts also have a combinatorial structure. The key to computational materialism is a structural and causal isomorphism between the structure of conscious and cognitive states, and the structure of physical and computational states. The problem is that the isomorphism can't be an identity if we use ordinary physical ontology or even physically coarse-grained computational states in any ontology.

Empirically, we do not know in any very precise way what the brain locus of consciousness is. It's sort of spread around, the brain contains multiple copies of data... One of the strong reasons for the presumption that speculations about the physical correlate of consciousness being an "exact quantum-tensor-factor state machine" rather than a "coarse-grained synapse-and-ion-gate state machine" are bogus and irrelevant, is the presumption that the physical locus of consciousness is already known to be something like the latter. But it isn't; that is just a level of analysis that we happen to be comfortable with. The question is still empirically open, one reason why I would hold out hope for a quantum monism, rather than a functionalist dualism, being the answer.