Necessary to have folded sheets in colour (8)
I believe the answer is:
required
'necessary' is the definition.
(similar in meaning)
'folded sheets in colour' is the wordplay.
'folded sheets' becomes 'quire'.
'in' indicates putting letters inside.
'colour' becomes 'red' (red is a kind of colour).
'quire' placed inside 'red' is 'REQUIRED'.
'to have' acts as a link.
(Other definitions for required that I've seen before include "Needed" , "Not optional" , "Essential, compulsory" .)