I suppose this is all personal preference, which will vary from person to person of course. But since you asked for opinions, I will offer mine.
For me, it's a real turnoff when I see a bass for sale that I like, but it has been "graffiti'ed" with a permanent marker of some sort. I think it makes the bass look like crap. But then, I don't like the looks of tattoos and piercings on females either, but some guys love that look on a girl. Again, I am only speaking from my own personal preference on this.
When it comes right down to it, do what you want in life and be happy, regardless of what anyone else thinks! Because at the end of the day, the only opinion that matters is yours!