Paint it only in your dreams and leave the bass alone.
I can't tell you how many fine basses I have seen ruined with amateur paint jobs. Since you are asking about the best way to paint the bass, I believe you do not have a good understanding of what it takes to refinish an instrument.
Please, do yourself a favor and leave the bass alone.
EBMM picks the best wood for the naturals...best grain, nicest single pieces, best matchup of two pieces. But seriously, if you want to do it, get a professional to refinish it.