Pink fuel is about right (5)
I believe the answer is:
coral
'pink' is the definition.
(coral is a shade of pink)
'fuel is about right' is the wordplay.
'fuel' becomes 'coal' (coal is a kind of fuel).
'is about' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'coal' placed around 'r' is 'CORAL'.
(Other definitions for coral that I've seen before include "Pink marine substance" , "certain islands" , "Marine substance, often forms reef" , "Lobster or crab roe" , "Main resident" .)