Generate a full-page, simple line art coloring page featuring an bowel of robots. The composition should consist of a variety of robots different stages of growth. The vase should have a geometric shape with a slightly flared opening, positioned at the center of the page. The line art should be clean and crisp, with uniform thickness and minimal shading to provide a super-friendly coloring experience. Include a subtle background of faint, overlapping geometric shapes to add depth to the scene and provide additional coloring opportunities --ar 21:15