title: In Django form, custom SelectField and SelectMultipleField
body: <p>I am using Django everyday now for three month and it is really great. Fast web application development.</p>
  
  <p>I have still one thing that I cannot do exactly how I want to.
  It is the SelectField and SelectMultiple Field.</p>
  
  <p>I want to be able to put some args to an option of a Select.</p>
  
  <p>I finally success with the optgroup :</p>
  
  <pre><code>class EquipmentField(forms.ModelChoiceField):
      def __init__(self, queryset, **kwargs):
          super(forms.ModelChoiceField, self).__init__(**kwargs)
          self.queryset = queryset
          self.to_field_name=None
  
          group = None
          list = []
          self.choices = []
  
          for equipment in queryset:
              if not group:
                  group = equipment.type
  
              if group != equipment.type:
                  self.choices.append((group.name, list))
                  group = equipment.type
                  list = []
              else:
                  list.append((equipment.id, equipment.name))
  </code></pre>
  
  <p>But for another ModelForm, I have to change the background color of every option, using the color property of the model.</p>
  
  <p>Do you know how I can do that ?</p>
  
  <p>Thank you.</p>