Fruit: love assortment (6)
I believe the answer is:
Here is my best explanation:
'fruit' is the definition.
(orange is a kind of fruit)
'love assortment' is the subsidiary indication.
'love' becomes 'o' (In tennis, 'love' means 'zero').
'assortment' becomes 'range' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
(Other definitions for orange that I've seen before include "Colour of an onager?", "Round fruit (6)", "Between red and yellow on the spectrum", "Dutch royal house", "Fruit; pigment", "Belisha beacon colour", "Colour - fruit", "Order of the North", "An ogre (anag.)" and "Unrhymable word?".)