remove colors from Category fixture

fixtures/program/category.json

@@ -7,7 +7,6 @@
       "abbrev": "I",
       "slug": "interkulturell",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -19,7 +18,6 @@
       "abbrev": "L",
       "slug": "lokalbezug",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -31,7 +29,6 @@
       "abbrev": "Mi",
       "slug": "minderheiten",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -43,7 +40,6 @@
       "abbrev": "W",
       "slug": "wiederholung",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -55,7 +51,6 @@
       "abbrev": "M",
       "slug": "mehr-fremdsprachig",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -67,7 +62,6 @@
       "abbrev": "F",
       "slug": "frauenschwerpunkt",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -79,7 +73,6 @@
       "abbrev": "Ö",
       "slug": "osterreichische-musik",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   },
@@ -91,7 +84,6 @@
       "abbrev": "U",
       "slug": "sendungsubernahme",
       "is_active": true,
-      "color": "",
       "description": ""
     }
   }