I don't know based on the rulebook.

The provided rulebook context explains how the Scout action allows you to acquire Wild cards (see page 11), and how the Build action requires discarding an appropriate card, including Wild cards (see page 9). However, the context does not specify whether cards gained from the Scout action are immediately added to your hand and available for use in the same turn, or if they are only available on a subsequent turn.

To answer this question definitively, the rulebook would need to clarify:

• When Wild cards gained from the Scout action are added to your hand.
• Whether you can use cards gained during an action for your second action in the same turn.

Without this information, the rulebook context is insufficient to answer your question.

Source: Core Rulebook (pp. 10, 11, 6, 9)