Final answer:
The provided information does not specify the color of Steven's graduation gown but discusses historical artistic details and symbolism. Steven mentions purple in relation to imperial power in historical contexts, but no direct link to his gown's color is made.
Step-by-step explanation:
The information provided by Steven does not explicitly mention the color of Steven's graduation gown. Instead, it describes various historical art details, such as the depiction of a character holding a scepter, the awe-inspiring effects of glasswork in the twelfth century, a figure with elaborate clothing and jewelry, and the significance of color in portraying power and association in art.
However, Steven does mention that Maximian wears purple, which is often associated with royalty and could potentially be related to the color of graduation gowns if they were to follow historical traditions of associating purple with authority. Despite this, no clear statement about the specific color of Steven's graduation gown is made.
Without additional context or information, we cannot accurately determine the color of Steven's graduation gown. Artistic details given by Steven are more focused on historical art and symbolism rather than contemporary academic attire.