import React from 'react';
import ReactDom from 'react-dom';

const totalColor=40;
const Box=(props)=>{...}

class RandomColorApp extends React.Component{
    constructor(props){
        super(props);
        const boxes = new Array(totalColor).fill().map(this.randomColor,this);
        this.state={boxes}

        setInterval(()=>{

           const randomIndex1=Math.floor(Math.random()*3)
           const randomIndex2=Math.floor(Math.random()*3)
           if(randomIndex1!==randomIndex2){
              console.log(randomIndex1,randomIndex2)
           }
        },1000);
    }

    randomColor(){...}
    render(){...}

}

RandomColorApp.defaultProps={colors:[...]}

ReactDom.render(<RandomColorApp/>,document.getElementById('app'));