Hit originally contained Heroes sample (6)
I believe the answer is:
swatch
'sample' is the definition.
(I have seen 'Sample of cloth' mean 'swatch' so perhaps 'sample' could also mean 'swatch')
'hit originally contained heroes' is the wordplay.
'hit' becomes 'swat' (swatting is a kind of hitting**).
'originally' says to take the initial letters.
The first letters of 'contained heroes' is 'ch'.
'swat'+'ch'='SWATCH'
(Other definitions for swatch that I've seen before include "Sample book" , "Sample piece of cloth or other material" , "Model" , "Carpet sample" , "Sample of fabric" .)