JSブリッジモード

class Color{
    constructor(name){
        this.name = name
    }
}

class Shape{
    constructor(name,color){
        this.name = name
        this.color = color
    }
    draw(){
        console.log(`${this.name} --- ${this.color.name}`)
    }
}

let red = new Color('red')
let yellow = new Color('yellow')
let circle = new Shape('circle',red)

circle.draw()