Red coat in a new fashion style (3,4)
I believe the answer is:
art deco
'style' is the definition.
(decorative style)
'red coat in a new fashion' is the wordplay.
'red coat' anagrams to 'ART DECO'.
However, I'm not clear how this is indicated.
Can you help me to learn more?
(Other definitions for art deco that I've seen before include "1920s and 1930s style of ornamentation" , "1920-30s design style" , "Style popular in the 1920s and '30s" , "Nineteen twenty's and thirties style" , "1920s and 1930s ornamental style" .)