A New Theory of Color
I will first state the theory as simply and clearly as possible, and then I will consider what may be said in its favor. I call the theory “Double Object Dispositional Primitivism” (DODP) or just “the double object theory”.  Its tenets are as follows: When you see an ordinary object the color it is seen to have is a simple monadic property of the object’s surface (not a disposition). This property is generated from within the mind and is projected onto the seen object. The mind has a disposition (power) to project color qualities onto seen objects, and it is a necessary and sufficient condition for being (say) red that the object should elicit this disposition. The object is red in virtue of the fact that it triggers the mind’s disposition to project redness onto objects. Another type of mind might have a disposition to project blueness onto the same objects (say, Martians) and then the object would be blue for them. Color is relative. In addition to this object there is another object (intuitively, an object of physics) that is not itself red but which has a disposition to interact with the first disposition to give rise to experiences of red. This disposition is by no means identical to redness, but it is closely related to it: the object that has it triggers perceptions of the primitive property of redness. The physical object interacts with a mind to make that mind activate its disposition to see things as red; it is “red-inducing”. The object induces perceptions of red (in certain perceivers) in which the primitive property of redness is projected onto an object that is not identical with the inducing object. So there are two connected ontological levels: a perceptual object that has the primitive property of being red, and a physical object that lacks that property but which has a disposition to cause perceptions of red (in conjunction with the mind’s disposition to see certain objects as red). It is strictly false to describe this second object as red, though it is natural to do so given its actual role in producing experiences of red. In short: perceptual objects are primitively red while physical objects are dispositionally red (i.e. not really red). We see the primitive property of redness, but we never see the dispositional property associated with it. These two properties are possessed by two distinct objects (think the manifest image and the scientific image).
The mind has a disposition to see certain objects as red and this disposition can be triggered by physical objects. When this happens an object is seen as red, but that object is not the triggering object. The mental disposition can in principle be triggered in other ways too, as when a brain in a vat sees things as red because of stimulation of the visual centers. Here no physical object operates to trigger the disposition (i.e. an object in the perceiver’s environment acting on the eyes) and yet an object is seen. Hallucinated objects can be red too. This is hard to account for under the classical dispositional theory, since that theory supposes that only (existing) physical objects with certain dispositions can be red. But to be red is not just to be a physical object that is disposed to produce red experiences by normal perception, because hallucinated objects can also be red. The important factor is the mind’s disposition to generate such experiences, not the de facto dispositions of the physical world. Generally the mental disposition is triggered by the usual environmental objects, but it can also be triggered in other ways, as with the brain in a vat scenario. Suppose I say, “That tomato is red”: this is true if I am referring to a perceptual object of a certain kind, whether real or hallucinated, but not if I am referring to the physical object associated with that object. The objects of physics have no color (they lack primitive color properties), though they do have dispositions to produce color experiences (in conjunction with suitable minds). Those objects had no color before perceivers came along and they have none now, though they do now possess a disposition they lacked earlier. They do not have secondary as well as primary qualities (or else physics would be required to mention them). The objects that have colors are different objects—perceptual objects. And colored objects can be perceived even by a brain in a vat. To use a familiar terminology, phenomenal objects are red but noumenal objects are not, despite being closely tied to phenomenal objects. 
What nice things can be said about the double object theory? First, we do justice to the phenomenal primitiveness of colors, their manifest simplicity, and to the fact that we can see them (as we could not if colors were identical to dispositions). Second, we acknowledge the role of mental dispositions in grounding attributions of color, as well as the role of external objects in eliciting perceptions of color. We are not completely wide of the mark in calling physical objects colored—though it is a question how often we really do this, given that we are normally talking about perceptual objects not the objects of physics. The relationship between our ordinary ontology of tables, tomatoes, and tulips, on the one hand, and the objects described in physics, on the other, is obscure; and it is by no means obvious that we speak of the latter when referring to the former. In any case, according to DODP there are two objects at play here, one of which is red, and the other of which is not (though it has a disposition to cause experiences of objects of the first kind to look red). It is not one and the same entity that is both red and disposed to look red. Certainly, the color red is not the categorical basis of the disposition to appear red—that will be a matter of the physical properties of the object belonging to physics. There are three levels at work here: the physical properties of the physical object that ground its disposition to give rise to appearances; the disposition itself; and the primitive property that perceptual objects possess (and appear to possess). Only the last of these is perceptible. The crucial component is the disposition of the mind to see things a certain way: once that disposition is activated color comes into the world, projected by the mind.
What might be said against the theory? Perhaps some will find the doubling of objects objectionable—they will prefer to attribute color to the objects of physics. In fact the spirit of the theory would be largely preserved by this move, with the primitive color properties instantiated in the same object as the disposition to cause color experiences—we can still keep these properties distinct, as well as invoke projection to explain the presence of the primitive property in the object. I have formulated the theory in the double-object way because I favor this position on independent grounds (having to do with hallucinations, intentional objects, and brains in vats). I also think it undesirable to locate colors in the world studied by physics, since physics makes no mention of these properties (their relativity to perceivers disqualifies them to begin with). I think of perceptual objects as an ontological layer over and above the objects described by physics (compare Eddington on the “two tables”). Artifacts and organisms, in particular, should not be seen as individuated and constituted by the categories proper to physics, but as a distinct ontological layer (though no doubt dependent on the physical level in some way). Color properties attach to this common sense level not to the rarefied level occupied by physics (the “absolute conception”). Still, it would be possible to apply the apparatus of DODP to a single-level ontology, the essential idea being that colors are primitive properties bestowed on the world by dispositions of the mind (coupled with the action of physical objects).
That idea might itself provoke further dissent: for how can the mind generate these properties from within its own resources? Isn’t this mysterious and magical-seeming? I totally agree: how the mind (brain) manufactures color properties is indeed mysterious, like many things about the mind. But this is not a fatal objection to the theory, simply a fact about the mind that needs to be acknowledged, i.e. that there is much about it that we cannot explain. Other theories avoid such mysteries by advocating reductive accounts of color—as that colors are reducible to electromagnetic wavelengths or that they are logical constructions from subjective qualia conceived as inner sensations. But these attempts at reduction are implausible (for reasons I won’t go into), the primitive property theory emerging as superior—though it does indeed lead to problems of intelligibility. Where do these remarkable properties come from? Does the mind create them itself or find them elsewhere (in a Platonic world of color universals, say)? How exactly are they “projected” onto objects? The theory raises plenty of puzzles, to be sure, but it might yet be true, since the truth is sometimes mysterious.  What the theory does is arrange the facts into an intelligible structure, aiming to respect phenomenology and logical coherence. Instead of working just with physical objects and their dispositions, it invokes an extra layer of non-dispositional properties and places them within a mind possessing certain projective dispositions. Perceptual objects thus have exactly the properties they appear to have, while we avoid treating colors as mind-independent. Colors have no place in physics, but they are front and center in our ordinary experience of things, just as they seem to be.
 I first wrote about color in The Subjective View (1983), then in “Another Look at Color” (1996), and now in this paper (2018). At each point I have modified the position that came before, while retaining the basic outlook. The successive theories have become more complicated as time has gone by.
 This terminology is not strictly accurate because “noumenal” is generally taken to entail “unknowable”, but the objects of physics are not unknowable. Still, the terminology may be helpful in capturing the structure of the position.