The appearance of the specimen is usually reported only if it is abnormal. Red: Blood; porphyria; occasionally urates, phenolphthalein, or dihydroxyanthraquinone (Dorbane) (laxative use) Brown: Blood (acid hematin); alkaptonuria (urine turns brownish on standing); melanin (may be brown and turn black on standing) Dark orange: Bile, pyridium (a urinary tract disinfectant) pH Normal urine pH […]