Beauty suffused dandy amber light (3,4)
I believe the answer is:
fog lamp
'beauty suffused dandy' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'amber light' is the wordplay.
'amber' becomes 'fog' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'light' becomes 'lamp' (lamp is a kind of light).
'fog'+'lamp'='FOG-LAMP'
Can you help me to learn more?
(Other definitions for fog lamp that I've seen before include "shines amid the gloom" , "Driver's visibility aid in mist" , "Bright light used in poor driving conditions" , "Something that's light" , "Strong car headlight" .)