Ultimately prepared for revolution (3)

I believe the answer is:
red
'ultimately prepared for revolution' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'ultimately prepared for revolution' is the wordplay.
'ultimately' indicates one should take the final letters.
'for' says to put letters next to each other (I've seen this in other clues).
'revolution' becomes 're' (I can't justify this - if you can you should give a lot more credence to this answer).
The last letter of 'prepared' is 'd'.
'd' after 're' is 'RED'.
Can you help me to learn more?
(Other definitions for red that I've seen before include "Colour of garnets" , "'If you see it, perhaps you're angry (3)'" , "- Cross; - carpet" , "Bordeaux claret, for instance" , "Carmine" .)
