The Compendium of Bheḷa 5.6.2

5.6.2

bahirlohitakāyas tu pāṇḍurantaḥ prakāśate | pūrvarūpamanuprāptaḥ sa mṛtyor ucyate naraḥ ||

When a man's body appears red on the outside but pale on the inside, / that man is said to have reached the premonitory symptom of death.