Brighter chess player first to resign (6)
I believe the answer is:
whiter
'brighter' is the definition.
('white' can be similar in meaning to 'bright')
'chess player first to resign' is the wordplay.
'chess player' becomes 'white' (one of the two players in a game of chess).
'first to' indicates taking the first letters.
The first letter of 'resign' is 'r'.
'white'+'r'='WHITER'
(Other definitions for whiter that I've seen before include "''A ... Shade of Pale'' (Procul Harum)" , "A - - Shade of Pale (1960s song)" , "More like the snow" .)