Out with squire changing colour (9)
I believe the answer is:
turquoise
'colour' is the definition.
(I know that turquoise is a colour)
'out with squire changing' is the wordplay.
'with' is a charade indicator (letters next to each other).
'changing' is an anagram indicator.
'out' put after 'squire' is 'squireout'.
'squireout' with letters rearranged gives 'TURQUOISE'.
(Other definitions for turquoise that I've seen before include "not quite green" , "Shade of blue - gemstone" , "Precious stone" , "Greenish-blue colour" , "Greenish-blue stone" .)