title: Peewee, Python, get data in column foreign key
body: <p>Hi I have a database and 2 tables, </p>
  
  <pre><code>color: color_id | color_name | color_type
  fruit: fruit_id | color | fruit_name
  </code></pre>
  
  <p>My 'color' in fruit's table is a foreignkey draging to 'color_id' in color's table.</p>
  
  <p>So, with Peewee &amp; Python I want to get 'color' in fruit's table, but I alsways receive a 'None'.</p>
  
  <pre><code>fruits= Fruit.select() 
  for fruit in fruits:    
       c = fruit.color   
       print(c)
  </code></pre>
  
  <p>I tried with</p>
  
  <pre><code>fruits = Fruit.get()
  </code></pre>
  
  <p>But here I can't iterate with it. 
  I show you my model: </p>
  
  <pre><code>class Fruit(BaseModel):
      fruit_id= CharField()
      name = Charfield()
      color= ForeignKeyField(column_name='color', field='color', model=Color, null=True)
  
      class Meta:
          table_name = 'fruit'
  </code></pre>
  
  <p>Do you have any idea how I can get the value inside my column 'color' in my table 'fruit' ? Thanx</p>