Use black as default color for foreground

aleksis/apps/chronos/migrations/0007_advanced_models_from_untis.py

@@ -91,7 +91,7 @@ class Migration(migrations.Migration):
                 ('extended_data', django.contrib.postgres.fields.jsonb.JSONField(default=dict, editable=False)),
                 ('short_name', models.CharField(max_length=10, verbose_name='Short name')),
                 ('name', models.CharField(max_length=50, verbose_name='Long name')),
-                ('colour_fg', colorfield.fields.ColorField(default='#FFFFFF', max_length=18)),
+                ('colour_fg', colorfield.fields.ColorField(default='#000000', max_length=18)),
                 ('colour_bg', colorfield.fields.ColorField(default='#FFFFFF', max_length=18)),
             ],
             options={

aleksis/apps/chronos/models.py

@@ -644,7 +644,7 @@ class Holiday(ExtensibleModel):
 class SupervisionArea(ExtensibleModel):
     short_name = models.CharField(verbose_name=_("Short name"), max_length=10)
     name = models.CharField(verbose_name=_("Long name"), max_length=50)
-    colour_fg = ColorField()
+    colour_fg = ColorField(default="#000000")
     colour_bg = ColorField()
 
     class Meta: