This is a stupid joke based on a song from 1996.

dishwalla.js

var cars = {
  "acura": {
    "color": "blue",
    "year": 2009
  },
  "buick": {
    "color": "gray",
    "year": 2010
  },
  "chevy": {
    "color": "white",
    "year": 2013
  },
  "datsun": {
    "color": "blue",
    "year": 1972
  },
  "fiat": {
    "color": "yellow",
    "year": 2010
  },
  "hudson": {
    "color": "blue",
    "year": 1950
  }
}

var blue_cars = 0;

Object.keys(cars).forEach(function(car){
    if( cars[car].color == 'blue' ){
        blue_cars++;
    }
});