Said to be more adventurous in Colorado city (7)
I believe the answer is:
boulder
'colorado city' is the definition.
(I've seen this before)
'said to be more adventurous' is the wordplay.
'said to be' indicates a 'sounds like' (homophone) clue.
'more adventurous' becomes 'bolder' ('bold' is associated in meaning with 'adventurous').
'bolder' is a homophone of 'BOULDER'.
'in' acts as a link.
(Other definitions for boulder that I've seen before include "Big rock" , "Large smooth rounded rock" , "Large stone" , "US city" , "Large, loose eroded rock" .)