Ancient Chinese Reference
From Fernand Braudel’s 1963 A History of Civilizations:
“But the immortality sought by the [early] Taoists was not only the salvation of the soul: it was also physical immortality, thanks to a series of recipes for long life…above all cinnabar (red mercuric sulphide) when it had nine times been transformed into mercury and back again so as to make ‘the red pill of immortality’…which carries the adept, now immortal, to the abode of the gods. To avoid troubling the world of the living, he pretends to die…leaving behind him a stick or a sword which he has made look exactly like a corpse.”
Nothing yet about a blue pill.