Two critical aspects of employment law in Colorado are the Worker Adjustment and Retraining Notification (WARN) Act and the "at-will" employment doctrine. The WARN Act mandates 60-day notice of mass layoffs or closures, offering affected employees time to prepare for job loss. However, Colorado also follows the "at-will" employment doctrine, which allows employers to terminate employees without giving a reason, except when it's against public policy or contractual agreements.