fix: change carColor type to Mixed for improved flexibility

server/routers/dry-wash/model/order.js

@@ -15,7 +15,7 @@ const schema = new Schema({
         type: Number,
         required: true
     },
-    carColor: String,
+    carColor: Schema.Types.Mixed,
     startWashTime: {
         type: Date,
         required: true