Urine color in catheter bag goes from yellowish to a darker shade, prostate problem, dementia, no respiration problems. possible reasons?

Here are some...: Urine color in draining bag is expected to change over time reflecting urine concentration, blood in urine, foods consumption, even drug use, or bacterial colonization, etc., but clinically insignificant as long as being afebrile & feeling comfortable. Then keep on adequate catheter care stressing: no catheter traction onto penis, bag always below bladder level, daily cleansing urethral opening...