Stain wood navy blue last of all (3)
I believe the answer is:
dye
'stain' is the definition.
(I've seen this before)
'wood navy blue last of all' is the wordplay.
'last of all' indicates one should take the final letters.
The final letters of 'wood navy blue' are 'DYE'.
(Other definitions for dye that I've seen before include "Liquid used to change colour of clothes" , "Tint" , "Colouring material" , "Colouring; sounds like fade" , "Staining material" .)