Charlotte Forever lyrics translation help needed

Hi everybody,
This song is about a very sad and broken man's sexual love for his daughter. The couple are Serge and Charlotte Gainsbourg. At the end of the song, after they both profess their love for each other, Charlotte sings,

"Vu ni vu ni couleur."

Does anyone have any idea what this means? I am told it cannot be translated literally. Is there an equivalent English idiom?

lightning

To me this doesn't mean anything Xd Literally it would be: 'Seen not, seen not colour'
The correct expression is 'ni vu, ni connu' which you use when you did something for nobody to notice.

Thanks, that agrees with what other French speaking people have told me.