My code is as follows...

```
class Todo(models.Model):
    state_choice = (('To Do','To Do'),('Doing','Doing'),('Done','Done'))

    def get_color_depends_state(self):
      if self.state:
         if self.state == 'To Do':
             self.color_code = '87CEEB'
         elif self.state == 'Doing':
            self.color_code = '7D3C98'
         elif self.state == 'Done':
            self.color_code = '00FF7F'  

    state = models.CharField(max_length=200,choices=state_choice,default='todo')

    color_code = models.CharField(max_length=6, default=self.get_color_depends_state)

```

My field color\_code depends on the values of state field. I am trying to call the function from the color\_code field but it is giving errors like *self not defined* or *module has no attribute get\_color\_depends\_state*.

How I can call an instance method from field which intern depends on other field values(*Here state*)