When you are looking at a specific kind of red light emitted by hydrogen. This color-inverted photo was taken in October of last year by the Big Bear Solar Observatory's 1.6 meter New Solar Telescope. They say it looks like a rose, but I definitely see a thistle.
The photo is of a relatively small sunspot in active solar region 2177. The "petals" are fibrils, tubes of hot plasma confined by magnetism. You can see a colorized and contrast-adjusted image by Alan Friedman here.