Water colour artist queues up at openings (4)
I believe the answer is:
aqua
'water colour' is the definition.
'aqua' can be an answer for 'colour' (aqua is a kind of colour). I'm not certain of the 'water' bit.
'artist queues up at openings' is the wordplay.
'openings' indicates taking the first letters (I've seen 'opening of' mean this).
The first letters of 'artist queues up at' is 'AQUA'.
Can you help me to learn more?
(Other definitions for aqua that I've seen before include "(Denoting) water (Lat)" , "Water; pale blue colour" , "- - Libra" , "Blue tinged with green" , "which supports boats?" .)