The new version is a brightly coloured float (7)
I believe the answer is:
redraft
'the new version' is the definition.
(I've seen this before)
'brightly coloured float' is the wordplay.
'brightly coloured' becomes 'red' (similar in meaning. I am not sure about the 'brightly' bit.).
'float' becomes 'raft' (raft is a kind of float).
'red'+'raft'='REDRAFT'
'is a' acts as a link.
Can you help me to learn more?
(Other definitions for redraft that I've seen before include "Produce a new version of a document" , "Altered document" , "Corrected version" , "Make a copy" , "Sketch a new plan" .)