Though you frame your question in terms of perception, you seem mainly concerned with the specific sense of sight. Independently of Aristotle, it is not quite clear what the proper object of vision or sight is or whether there could be such a thing. The problem is brought out by G.J. Warnock in discussing Berkeley:
After referring to the proper objects of taste and smell Warnock
..This list has at least one important peculiarity which Berkeley does
not bring out. It is not, so to speak, a homogeneous list; the supposed 'proper object' of sight is oddly unlike those of hearing, taste and smell. We can speak of the sound of a car, the taste of an orange,
the smell of a geranium. But in the case of sight there is nothing
analogous to this. . . . I heard the sound of a car; I smelled the
smell of the geraniums; I saw the . . . of a tree. There is no expression that fills the gap in the last of these sentences, in the way in
which 'sound' and 'smell' find an ordinary, natural place in the
others. Certainly 'light and colours' would be completely gut of
place in this context. (J. H. Woodger, 'Proper Objects', Mind, Vol. 65, No. 260 (Oct., 1956), pp. 510-515: 510-511.)
Aristotle appears (De Anima, II.6) to supply the gap with 'colour', a point considered below.
Aristotle on proper, 'common' and incidental objects of the senses
But we must grasp in general in connection with perception as a whole, that the sense is the recipient of the perceived forms (ton aisthetikon eidon) without their matter, as the wax takes the sign from the ring without the iron or gold - it takes, that is, the gold and bronze sign but not as gold or bronze'. (De Anima, II.12 : Lawson-Tancred: 187.)
Now in the case of each sense we must speak first about the sense-objects. The sense-object is spoken of in three ways ... Of the first two, one that is special [proper: GT] to each sense, the other that is common to all. Now I call that sense-object special [idion] that does not admit of being perceived by another sense and about which it is impossible to be deceived, as sight is connected with colour [opsis kromatos], hearing with sound and taste with flavour.
The common [koinon] objects ... are movement, rest, number, shape and size, such being not special to any one sense but common to all. For of course [for instance] a movement will be perceptible to both touch and sight.
Finally, those sense-objects are called incidental [kata sumbebekos] that are like the white thing's being the son of Diares. For this we perceive incidentally, for it is incidental to the white thing we perceive. (Lawson-Tancred: 172-3.)
Sight, colour and form
De Anima, II.7 is rather more nuanced in identifying the object of sight with colour :
While that which is the object of sight is the visible, and this comprises both colour and something which though it can be given by an account has no name. (Lawson-Tancred: 173.)
The object of sight (if we bypass the tautologous 'the visible') is colour; but colour can be seen only when a transparent substance, namely light, is actualised. Colours cannot be seen unless this substance is actualised; and so colour is not an unmediated object of vision. But it is still, so far as I can make out, the proper object of vision.
If I see a tree, grant that in conditions of standard illumination I see colour(s). As far as concerns vision, these colours are the sensible form of the tree. So Aristotle would supply Warnock's dots with : 'I saw the colour(s) of a tree'. Of course, a tree is more than its colours. The sensible forms of the tree are its texture and temperature if I touch it, its odour if I smell it, its taste if (admittedly oddly !) I lick it, its sound if it soughs in the wind.
I think there are good reasons for accepting that Aristotelian sensible forms are tropes or trope-like.
To fix ideas :
This sheet of paper is white. So is my shirt. In virtue of what are both
white? Classical nominalism allows only concrete particular objects, and
no universal properties. Classical realism appeals to universals, shared,
or perhaps instantiated, by concrete objects, in dealing with the idea that
various objects could have the same property. These theories have well
known difficulties. Tropes are entities introduced in order to solve the
vexing problems of universals and particulars; trope theory is an alternative
to traditional realist and nominalist theories.
The main idea in trope theory is that tropes are abstract particulars:
they are things like the whiteness of this paper, the hardness of the ball.
The ball is hard because there is a trope, the hardness of the ball, and
not because the ball participates in the universal hardness. (Fredrik Stjernberg, 'An Argument against the Trope Theory', Erkenntnis (1975-), Vol. 59, No. 1 (Jul., 2003), pp. 37-46: 37.)
It seems to me quite in line with this to say that when I see the oak tree at the end of my garden, I see the colour(s) of the tree, its Aristotelian visual sensible form, and there is a trope - namely the greenness and brownness of this particular tree. Such a view fits well with Aristotle's account of universals in which universals are to be understood neither nominalistically nor realistically but as belonging to - inhering in - individual subjects and not existing apart from them (Metaphysics, 1038b).
Aristotle, De Anima, tr. H. C Lawson-Tancred. Published by Penguin Books Ltd 1987-01-29, London (1987)
ISBN 10: 0140444718 ISBN 13: 9780140444711
Fredrik Stjernberg, 'An Argument against the Trope Theory', Erkenntnis (1975-), Vol. 59, No. 1 (Jul., 2003), pp. 37-46.
J. H. Woodger, 'Proper Objects', Mind, Vol. 65, No. 260 (Oct., 1956), pp. 510-515.