I'm new to JavaScript and prototype-based programming. I know you can define inherited classes like class Circle extends Shape {}, but class is mostly a syntactic sugar of constructor functions, so is there any equivalent for inheritance of functions in JavaScript?

In other words, how can I define an inherited function without class keyword, like this:

var Shape = function() {
  this.getColor = function() {alert('Some color!')};
};

//Something like this:
var Circle = Function.create(Shape);

var circle1 = new Circle;

//With all below conditions:
console.log(Circle.__proto__ == Shape)                     // true
console.log(Circle.prototype.__proto__ == Shape.prototype) // true
console.log(circle1 instanceof Shape)                      // true
console.log(Object.getOwnPropertyNames(circle1))           // Array [ "getColor" ]

I've searched some articles but last condition wasn't achieved in them and getColor was an inherited property, rather than being a member of the circle1 itself.