I go on trail that's colourful (10)
I believe the answer is:
iridescent
'colourful' is the definition.
(similar in meaning)
'i go on trail' is the wordplay.
'go on' becomes 'ride' (riding is a kind of going on).
'trail' becomes 'scent' (an animal's trail is its scent).
'i'+'ride'+'scent'='IRIDESCENT'
'that's' is the link.
(Other definitions for iridescent that I've seen before include "Shimmering with rainbow colours (anag of 1 across, 9 and 23)" , "Showing luminous colours" , "Like a rainbow" , "changing colour" , "with a glittering display" .)