Fruit's extremely arresting dull surface (6)
I believe the answer is:
tomato
'fruit's' is the definition.
(type of fruit)
'extremely arresting dull surface' is the wordplay.
'extremely' becomes 'too' (I've seen this in another clue).
'arresting' means one lot of letters goes inside another.
'dull surface' becomes 'mat' (I've seen this in another clue).
'too' enclosing 'mat' is 'TOMATO'.
(Other definitions for tomato that I've seen before include "A motto turned out to be fruit/veg" , "Shiny red fruit" , "A motto turned out to be fruit or veg" , "Fruit, often used as vegetable" , "Fruit-vegetable" .)