JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <div class="box">
    <div class="wrapper">
      <div class="wrapperOfColour">
        <label>
          Баланс красного
          <input type="range" min="0" max="255" step="1" value="50" name="red" id="red">
        </label>
      </div>
      <div class="wrapperOfColour">
        <label>
          Баланс зеленого
          <input type="range" min="0" max="255" step="1" value="50" name="green" id="green">
        </label>
      </div>
      <div class="wrapperOfColour">
        <label>
          Баланс синего
          <input type="range" min="0" max="255" step="1" value="50" name="blue" id="blue">
        </label>
      </div>
    </div>
    <div class="square">

    </div>
  </div>
</body>

CSS

.wrapper,
.square {
  border: 1px solid black;
  height: auto;
  border-radius: 5px;
}

.box {
  display: inline-block;
  border: 1px solid black;
  padding: 5px;
  margin-right: 15px;
}

label {
  margin: 3%;
  display: inline-block;
  width: 100%;
}

p {
  text-align: center;
}

.wrapper {
  float: left;
  width: 400px;
  height: 160px;
}

.wrapperOfColour {
  display: float;
  width: 100%;
}

.square {
  float: right;
  width: 160px;
  height: 160px;
}

.square:after {
  clear: both;
}

JavaScript

const inputs = document.querySelectorAll("input");

const handleUpdate = event => {
  document.querySelector(".square").style.background = `rgb(${inputs[0].value}, ${inputs[1].value}, ${inputs[2].value})`;
};

inputs.forEach(input => input.addEventListener("change", handleUpdate));
inputs.forEach(input => input.addEventListener("mousemove", handleUpdate));