How did 真っ赤 came to mean "downright"?


We know that 真っ赤 means "deep red," but how did it come to mean 'downright', as
in 真っ赤な嘘 (outright lie)?




真っ赤 doesn't mean deep red, it's an emphatic expression of being red.

It comes form suffix ma and reduplicated adjectives.

  1. ma aka aka --> makkakka --> makka (まっかっか is still a word)
  2. ma kuro kuro --> makkuro

Edit: Sorry, my answer was irrelevant to OP's question.

