For visual learners, concepts have always been easier to understand when one could picture them as something else.
For some, even months have colours. January can be bright blue, July pink and October orange, for instance. Maybe it has something to do with the feeling of each season, or maybe it is simply a way of making something abstract feel more real.
Sexuality has always worked the same way for many. Different kinds of love feel like different genres, not because they can be neatly categorised, but because they carry different textures, emotions and rhythms.