Disclaimer: I'm a loathsome, offensive brute.
In the name of cleanliness, I don't think a black grille would look good on a white 4th gen 4Runner. Sounds tacky. If you had badly faded cladding or something, there's something to plastidip. Maybe if the grille is offset by other black items, like a black steel bumper, it would fit better. Otherwise, it looks like a void from afar... a lack of style, if you will. Hence why black wheels can be so overrated, almost any ugly wheel looks better in black because you can't see them until you're close. I have black wheels on one of my trucks because it's harder to notice there's only 3 matching wheels that way.
Plastidipping random items reminds me of something you'd find on a ricer's Honda, they often like changing the color of the gas door for whatever reason. Black hoods should die a horrible death. Cue whatever loser says "If they like it then that's all that matters."
Sick gas door, bro... There's better things to use plastidip for, IMO. Black badges on a white 4Runner would be a good use.