Não sei porque o obstacle ta pegando a cor do ground em vez de pegar a do obtcs.color. augem me ajuda pfv

//variaves
var canvas = '';
var ctx = "";
var WIDTH = "";
var HEIGHT = "";
var frame = "0";
var amountOfJumps = 1;

var ground = {
    y: 550,
    height: 50,
    cor: "#2E4053",

    drown: function() {
        ctx.fillStyle = this.cor;
        ctx.fillRect(0, this.y, WIDTH, this.height);
    }

}

var block = {
    x: 50,
    y: 0,
    width: 50,
    height: 50,
    cor: "#8E44AD",
    gravity: 1.6,
    speed: 0,
    strengthOfJump: 23.6,
    AOJ: 0,

    update: function() {
        this.speed += this.gravity;
        this.y += this.speed;

        if(this.y > ground.y - this.height) {
            this.y = ground.y - this.height;
            this.AOJ = 0;
        }
    },

    jump: function() {
        if(this.AOJ < amountOfJumps) {
            this.speed = -this.strengthOfJump;
            this.AOJ++;
        }
    },

    drown: function() {
        ctx.fillStyle = this.cor;
        ctx.fillRect(this.x, this.y, this.width, this.height);
    }
}

var obstacles = {
    _obtcs: [],
    color: ["#b03a2e", "#cb4335", "#a93226", "#e74c3c", "#c0392b", "#ec7063"],

    insert: function() {
        this._obtcs.push({
            x: 200,
            width: 30 + Math.floor(21 * Math.random()),
            height: 30 + Math.floor(90 * Math.random()),
            cor: this.color[Math.floor(5 * Math.random())]
        });
    },

    update: function() {

    },

    drown: function() {
        for (var i = 0, size = this._obtcs.length; i < size; i++) {
            var obtcs = this._obtcs[i];
            ctx.fillStyle = obtcs.color;
            ctx.fillRect(obtcs.x, ground.y - obtcs.height, obtcs.width, obtcs.height);
        }
    }
}

//funções
function click(event) {
    block.jump();
}

function main() {
    HEIGHT = window.innerHeight;
    WIDTH = window.innerWidth;

    if(WIDTH >= 500) {
        WIDTH = 600;
        HEIGHT = 600;
    }

    canvas = document.createElement("canvas");
    canvas.width = WIDTH;
    canvas.height = HEIGHT;
    canvas.style.border = "1px solid blue";

    ctx = canvas.getContext("2d");
    document.body.appendChild(canvas);

    document.addEventListener("mousedown", click);

    run();
}

function run() {
    update();
    drown();

    window.requestAnimationFrame(run);
}

function update() {
    frame++;

    block.update();
}

function drown() {
    ctx.fillStyle = "#B8B8B8";
    ctx.fillRect(0, 0, WIDTH, HEIGHT);
    
    ground.drown();
    obstacles.drown();
    block.drown();
}

main();