More white people in the leading position before (8)
I believe the answer is:
pearlier
'more white' is the definition.
('pearly' can be similar in meaning to 'white')
'people in the leading position before' is the wordplay.
'in the leading position' suggests taking the first letters.
'before' becomes 'earlier' (synonyms).
The initial letter of 'people' is 'p'.
'p'+'earlier'='PEARLIER'
(Other definitions for pearlier that I've seen before include "Ripe earl (anag.)" , "Rear pile (anag.)" .)