Charak Samhita
फेनिलं तनु रूक्षं च श्यावं चारुणमेव च । किंशुकोदकसङ्काशं सरुजं वाऽथ नीरुजम् ॥२१२॥
Now listen to the symptoms of vatika pradara. The menstrual blood is frothy, thin, rough, dark (blackish), reddish, resembling water of palasha flower in colour, comes with or without pain.
english translation
phenilaM tanu rUkSaM ca zyAvaM cAruNameva ca । kiMzukodakasaGkAzaM sarujaM vA'tha nIrujam ॥212॥
hk transliteration by Sanscript