Bicycle color, grass color and sky color are all part of the prompt.
>Cartoon illustration of a white pelican wearing a red scarf, riding a red bicycle along a gray road with white dashed lines; the pelican has a large orange beak and webbed orange feet pedaling, with white motion lines behind it; the background shows a light blue sky with white clouds, a yellow sun, two small black birds in flight, and green grass with tiny white flowers in the foreground
No, the prompt I always use is "Generate an SVG of a pelican riding a bicycle".
That wasn't the prompt. That text was generated by asking the model to describe an image and feeding it a rendering of the SVG it had previously generated.