Labour has long been identified with red, a political colour traditionally affiliated with socialism and the labour movement. The party conference in 1931 passed a motion "That this conference adopts Party Colours, which should be uniform throughout the country, colours to be red and gold". Since the party's inception, the red flag has been Labour's official symbol; the flag has been associated with socialism and revolution ever since the 1789 French Revolution and the revolutions of 1848. The red rose, a symbol of social democracy, was adopted as the party symbol in 1986 as part of a rebranding exercise and is now incorporated into the party logo.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When was the blue rose adopted as a symbol?
unanswerable