Corsa-B.uk - Vauxhall, Opel and Holden Corsa B Owners Club

hello all i i sprayed my spoiler a while ago using halfords pre mixed up paint (vauxhall flame red 79L)
and it came out 2 dark i was wondering if i went in and got it mixed up would it come out any better ? or would i b aswell paying 70 quid and getting it down proper ?

Can also depend on Primer colour you used.

people has said that to me ? i used red primer just like it said on the tin ? ive been told i should have used a yellow ? the spoiler was black before ?