What is the ruling on the prayer of a woman who sees very light bleeding after a D&C procedure, the color of which changes between pink, red, and brown, and she is unable to distinguish whether it is menstruation or not?

If a woman sees blood at a time when it could be considered menstruation, then it is menstruation, because the default assumption is that it is healthy blood. Light bleeding that is not preceded or followed by other bleeding is considered menstruation by the majority of scholars if its duration reaches a day and a night, which is their minimum period for menstruation. The Malikis and Shaykh al-Islam Ibn Taymiyyah hold that there is no minimum limit for menstruation. According to this view, the blood is considered menstruation even if its duration does not reach a day and a night. As for brownish discharges (kudrah), if they appear after purity, they are considered menstruation during the accustomed period, but not at other times.