Least bright in colour (6)
I believe the answer is:
palest
(Other definitions for palest that I've seen before include "Of the lightest colour" , "Most light in colour" , "Most lightly coloured" , "Most blanched" .)
I believe the answer is:
palest
(Other definitions for palest that I've seen before include "Of the lightest colour" , "Most light in colour" , "Most lightly coloured" , "Most blanched" .)