The biological process that makes melanin — the pigment that determines skin color and protects skin from UV radiation.Initiated by MC1R activation, which increases cAMP, activating PKA, which activates MITF (the master melanocyte transcription factor). MITF upregulates tyrosinase, TRP-1, and TRP-2 — the three enzymes that convert tyrosine into eumelanin. The pathway is specific to melanocytes and is the molecular basis for both normal tanning and the therapeutic mechanism of afamelanotide in EPP.