1A vivid, deep shade of red; also used to describe a face flushed from embarrassment or excitement.
紅葉した山が真っ赤に染まっている。
The mountains have turned bright red with autumn leaves.
走ってきたせいで彼の顔は真っ赤だった。
His face was flushed bright red from running.
真っ赤なトマトを畑からもいできた。
I picked bright red tomatoes from the field.
日焼けで肩が真っ赤になってしまった。
My shoulders turned bright red from sunburn.
2An intensifying expression meaning something is completely, undeniably so — as in a blatant lie or total nonsense.
あのアリバイは真っ赤な嘘だとすぐにばれた。
That alibi was quickly revealed to be a downright lie.
彼の説明は真っ赤な間違いだったと後で判明した。
It later turned out that his explanation was completely wrong.