As any kind of paints watercolours consist of pigments and binders. For expensive professional paints manufacturers usually use Arabic gum as a binder and some additives like sugar, gelatine, fish glue, honey, and phenol (as a preservative).
Apart from expensive paints, honey-based watercolours are made of pigments, honey, dextrin (corn glue), and usually contain no phenol (quite toxic chemical). All these provide bright colours, moist but not watery consistency, and make them suitable even for young artists.
However, honey-based watercolours cannot be graded as professional ones due to low pigment load and HUE colours. Nevertheless, honey-based watercolours are always in demand and work very well for student and casual paintings. Their prices are very attractive and quality is very high compared to other paints in the same price range.