Refurbished room in mid-blue or gilt decoration (6)
I believe the answer is:
ormolu
'gilt decoration' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'refurbished room in mid-blue' is the wordplay.
'refurbished' indicates an anagram.
'in mid blue' becomes 'lu' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'room' anagrammed gives 'ormo'.
'ormo'+'lu'='ORMOLU'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for ormolu that I've seen before include "Gold-coloured ally used in decoration" , "Alloy of copper and zinc" , "Gold-like decoration" , "Gilt brass" , "golden material" .)