Random gradient background color

If you dont try to calculate the remaining % then it seems to work as you expect

let colors = ["#ffd0d2","#fffdd0","#d0fffd","#d0d2ff"];
    $(".main").children('section').each(function(){   
        let firstGradient = randomNumber(10,90);
        $(this).css(
            "background", "linear-gradient(141deg, "+colors[randomNumber(0,4)]+" "+firstGradient+"%, "+colors[randomNumber(0,4)] + ")"
        );
    });
    function randomNumber(min,max){
        return Math.floor((Math.random() * max) + min);
    }

section{
  display:block;
  height:200px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="main">
  <section></section>
  <section></section>
  <section></section>
</div>