polished for manipulating colors

polished.js

import styled from 'styled-components';
import { darken } from 'polished';

button {
      background: #7169c1;
      color: #fff;
      border: 0;
      border-radius: 4px;
      overflow: hidden;
      margin-top: auto;

      display: flex; 
      align-items: center;

      &:hover {
        background: ${darken(0.03, '#7169c1')};
      }
}