The definition is the human interpretation, the thing is the human perception.
Sight, taste, touch, sound, are the human perceptions of the environment, whereas red, sweet, smooth, loud, are the interpretations of the perceptions. Without the interpretation, colors, smells, textures, and noises are meaningless and therefore non-existent. For what we cannot interpret has no meaning beyond our perception, and thus does not exist.
*Takes a pedantic bow as if he knew what the heck he was talking about*