Can open the shade (4)
I believe the answer is:
tint
'shade' is the definition.
(synonyms)
'can open the' is the wordplay.
'can' becomes 'tin' (both are metal containers).
'open' says to take the initial letters (take the opening letter).
The initial letter of 'the' is 't'.
'tin'+'t'='TINT'
(Other definitions for tint that I've seen before include "Shade; colour slightly" , "(Softer variety of) colour" , "Hue, shade" , "work for coiffeuse?" , "Quality of colour" .)