Limit what label fields we expose on Dashboard::LabelsController#index

app/controllers/dashboard/labels_controller.rb

 class Dashboard::LabelsController < Dashboard::ApplicationController
   def index
+    labels = LabelsFinder.new(current_user).execute
+
     respond_to do |format|
-      format.json { render json: LabelsFinder.new(current_user).execute }
+      format.json { render json: labels.as_json(only: [:id, :title, :color]) }
     end
   end
 end