What activity was Mathias engaged in when he recognized the color yellow?

The activity during which Mathias recognized the color yellow is aligned with reading a book. When children engage in reading, particularly picture books that include various colors, they often learn to identify those colors through illustrations and text. Books provide a rich context for young children to make connections between words and visual elements, enhancing their understanding and recognition of colors.

In reading, Mathias would likely encounter the color yellow in pictures or descriptions, prompting him to identify and verbalize it. This scenario supports language development as well, as recognizing elements like colors in text helps build vocabulary and comprehension skills.

The other activities, while they could also involve color recognition, typically do not emphasize it in the same way a reading context does. For example, playing with crayons or doing a puzzle can include color recognition, but they are often more focused on the creative or problem-solving aspects rather than explicit identification linked to literacy.