Final answer:
To apply Blue, Accent 1 fill color to a shape, one must select the shape and use the Fill options to choose the color from the Theme Colors section.
Step-by-step explanation:
The question requires applying a specific fill color to a shape in a digital document or presentation, which typically involves using a software program that supports themes and color fills, such as Microsoft PowerPoint or a similar program. To accomplish this, you would select the shape, navigate to the Fill options or a similar formatting feature, then choose the desired color, in this case, Blue, Accent 1. This action corresponds to the Theme Colors available within the software, which are pre-defined color schemes designed to create a cohesive look throughout a document or presentation.