All of the vector art can be modified inside PowerPoint. Most of the artwork is setup as a grouped set of PowerPoint shapes.
Click on it once to select the group. With the group selected, you can resize the entire group or set a style to the entire group. Hold down the shift key while you resize it and the group will keep the aspect ratio and not get stretched out.
Click again, but on a specific piece inside the group to highlight just that shape. Now Right-click on that shape and you can use PowerPoint shape formatting to change things like color.