What does the red HSD color indicate?

The red HSD color signifies "Add Travel Wallet." In the context of SEPTA’s fare collection system, the red indication likely alerts users that their balance within the Travel Wallet is low or requires attention. This prompts riders to take action by adding funds to ensure smooth travel without interruptions due to insufficient balance.

In contrast, the other options—Trip Started, Validation Successful, and Trip Cancelled—would typically have different color codes to give immediate feedback about those specific actions or statuses within the fare system. Knowing the significance of color codes is crucial for users to manage their travel efficiently and avoid any inconveniences during their journeys.