class SelectWOA(Select):
    def create_option(self, name, value, label, selected, index,
                      subindex=None, attrs=None):
        option_dict = super(SelectWOA, self).create_option(name, value,
            label, selected, index, subindex=subindex, attrs=attrs)
            #Category.objects.
        try:
            option_dict['attrs']['style'] =  'color: ' +  Category.objects.get(name=label).color + ';'
        except:
            pass

        return option_dict

from django.forms import ChoiceField, ModelChoiceField
from category.models import Category
class ProductAdminForm(ModelForm):
    test_field = ModelChoiceField(queryset=Category.objects.all(), widget=SelectWOA())
    class Meta:
        model = Product
        exclude = ['category']
        fields = ('name', 'image', 'image2', 'category', 'test_field',)





from django.db import models
class ProductCastumAdmin(admin.ModelAdmin):
    #fields = ('name',)
    form = ProductAdminForm