2.0232 Incidentally: objects are colorless.

Right. They have no properties. They are the possibility of properties. That is to say, an object is not this or that degree of hardness, say, but the possibility of, logical space for, this or that degree of hardness. A color object, then, a possibility within the dimensions of color, would be not this or that color but the possibility of this or that color. Also worth considering is that ‘colorless’ here refers to Frege’s notion of color or tone, the purely subjective flavor of certain words.

“Roughly speaking” might not be the best translation of “Beiläufig gesprochen.” Gillian Russell says: “I think it can mean in passing (and so on a side note is definitely one way to translate it in general), but it can also mean something like casually. The other translation of the Tractatus that I have (Pears and McGuiness …) goes for "In a manner of speaking", which is kind of an interesting translation decision. I suspect that captures pretty much what Wittgenstein meant to convey, despite it's non-literality.” See http://www.logicandlanguage.net/archives/2006/03/roughly_speakin_1.html#comments. The most literal translation would be something like “By the way: objects are colorless,” which might be too casual, so “Incidentally: objects are colorless” might be best. Nordmann (p. 102) has “By the way: …” Black (p. 64) seems to think that “in a manner of speaking,” “roughly speaking,” “incidentally,” and “in passing” would all be acceptable translations of beiläufig gesprochen.

McManus p. 124: “My suggestion is that to declare that our talk ultimately rests on an immediate ‘seeing’ of ‘colourless objects’ is one step away from recognizing that the ‘project’ of explaining the ‘possibility’ of ‘meaningful’ talk leaves us nothing to say or think: our ‘experience’ of the pure and simple here is the experience of empty words.”