Change arrow colors in Bootstraps carousel

Question

I'm obviously missing something stupidly simple here. I have images with a white background so I want to be able to edit the arrows on the Bootstraps Carousel so they are visible. So many changing the color of the arrows (NOT the background like I've done).

CSS

.carousel-control-prev-icon, .carousel-control-next-icon {
    height: 100px;
    width: 100px;
    outline: black;
    background-color: rgba(0, 0, 0, 0.3);
    background-size: 100%, 100%;
    border-radius: 50%;
    border: 1px solid black;
}

Carousel HTML

<div class = 'col-md-9'>

    <div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">

        <ol class="carousel-indicators">
            <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
            <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
            <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
        </ol>

        <div class="carousel-inner" role="listbox">
            <div class="carousel-item active">
                <img class="d-block img-fluid" src="carousel/Bars%20and%20Dots.jpg" alt="First slide" class = 'img-responsive'>
            </div>

            <div class="carousel-item">
                <img class="d-block img-fluid" src="carousel/murial.jpg" alt="Second slide" class = 'img-responsive'>
            </div>

            <div class="carousel-item">
                <img class="d-block img-fluid" src="carousel/Upper%20Partialism%20album%20covers004white.jpg" alt="Third slide" class = 'img-responsive'>
            </div>
        </div>

        <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
            <span class="carousel-control-prev-icon" aria-hidden="true"></span>
            <span class="sr-only">Previous</span>
        </a>

        <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
            <span class="carousel-control-next-icon" aria-hidden="true"></span>
            <span class="sr-only">Next</span>
        </a>

    </div>

</div>

Answer 1

.carousel-control-prev-icon,
.carousel-control-next-icon {
  height: 100px;
  width: 100px;
  outline: black;
  background-size: 100%, 100%;
  border-radius: 50%;
  border: 1px solid black;
  background-image: none;
}

.carousel-control-next-icon:after
{
  content: '>';
  font-size: 55px;
  color: red;
}

.carousel-control-prev-icon:after {
  content: '<';
  font-size: 55px;
  color: red;
}