 A related question is which properties color experience represents things as having when it represents them as being colored. Since color experiences in principle could be systematically in error, this is distinct from the ontological question of which properties the colors are, though the same options suggest themselves. According to one position, when an experience represents that an apple is red, it represents that it has a disposition to cause certain kinds of experiences. (See Langsam 2000 and McDowell 1985) According to an opposed position, when an experience represents that an apple is red, it represents that it has a non-dispositional property (McGinn 1983, Johnston 1992, Boghossian and Velleman 1992). One version of the latter says that experience represents a primitive property that cannot be specified in non-chromatic terms (Broackes 1992, Campbell 2003). Yet another says experience is neutral on whether redness is or isn’t primitive. (Byrne and Hilbert 2003) Another question is whether colors are represented as being properties of external objects, or of sense-data (where these are private mental objects), or both.