JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.js"></script>
<canvas id="chart"></canvas>

JavaScript

const ctx = document.getElementById('chart').getContext('2d');
const data = [10, 20, 40, 30, 10, 55,60];
const colours = data.map((value) => value < 0 ? 'red' : 'green');

new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June", "July"],
    datasets: [{
      label: "My First dataset",
      borderColor: colours,
      backgroundColor: colours,
      data: data,
      fill: false,

    }]
  },
  options: {
    legend: {
    	display: false
    }
  }
})