Colour of small runabout on lease? (7)
I believe the answer is:
scarlet
'colour' is the definition.
(scarlet is a kind of colour)
'small runabout on lease?' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'runabout' becomes 'car'.
'on' is a charade indicator (letters next to each other).
'lease?' becomes 'let' ('let' can be a synonym of 'lease').
's'+'car'+'let'='SCARLET'
'of' is the link.
(Other definitions for scarlet that I've seen before include "Brilliant red colour" , "Shade of red" , "Vivid red" , "Cartels (anag.)" , "Clarets (anag.)" .)