Colourless stake (4)
I believe the answer is:
pale
This clue is a double definition.
'colourless' is the first definition.
(similar in meaning)
'stake' is the second definition.
(pale can mean a wooden stake or post)
(Other definitions for pale that I've seen before include "Upright member" , "Without much colour" , "wooden post" , "beyond which one is out of line?" , "Stake, lacking colour" .)