The severity of the red colour of urine depends on the cause of the symptom. If you have eaten a lot of red heart dragon fruit and mulberries before the symptom appeared and have no other uncomfortable symptoms, you do not need to worry too much, just drink more water and keep an eye out to see if the colour of your urine returns to normal next.
However, it is important to note that most red urine is a symptom associated with a disease and should not be ignored with care, if it is not clearly caused by taking a certain food and it returns quickly after stopping, you should seek prompt medical attention.