title: Change colors in scatterplot by category
body: <p>I am wondering how I can change the colors of my categories manually in the python code under instead of using cmap?</p>
  
  <p>The colors I want is the following hex color codes:</p>
  
  <p>Blue: #1f77b4</p>
  
  <p>Orange: #ff7f0e</p>
  
  <p>Green: #2ca02c</p>
  
  <p>Red: #d62728</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>d = """category1,05-01-2020
  category1,02-02-2020
  category3,06-03-2020
  category2,12-04-2020
  category4,07-05-2020
  
  """
  df = pd.read_csv(StringIO(d), sep=',', parse_dates=[1], header=None, names=['category','date'])
  
  
  fig, ax = plt.subplots()
  ax.scatter(df['date'],df['category'], marker='s', c=df['category'].astype('category').cat.codes, cmap='tab10')</code></pre>
  </div>
  </div>
  </p>
  
  <p>Help is appreciated!</p>