A coconut stall, pale greyish in colour (4)
I believe the answer is:
ashy
'pale greyish in colour' is the definition.
'ashy' can be an answer for 'pale' (I've seen this before). I am unsure of the 'greyish in colour' bit.
'a coconut stall' is the wordplay.
'coconut stall' becomes 'shy' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a'+'shy'='ASHY'
Can you help me to learn more?
(Other definitions for ashy that I've seen before include "Like, eg, volcanic dust" , "Like fireplace residue" , "Like burnt wood or coal" , "Leaden" , "evidence of recent fire" .)