Mixed so treads (8)
I believe the answer is:
assorted
'mixed so treads' is the definition.
'assorted' can be an answer for 'mixed' (I've seen this in another clue). I'm not sure about the 'so treads' bit.
'mixed so treads' is the wordplay.
'mixed' indicates an anagram.
'so'+'treads'='sotreads'
'sotreads' is an anagram of 'ASSORTED'.
Can you help me to learn more?
(Other definitions for assorted that I've seen before include "Of different kinds put together, say sweets" , "Manifold" , "Of various types put together" , "Odd-shaped" , "Various, diverse" .)