na-adjective, noun
very bright red; deep red; extremely flushed
Emphatic form of 真っ赤, describing an intense, vivid red color or a face that is deeply flushed (from embarrassment, anger, etc.). Often used in casual speech.
See also: 真っ赤 (まっか)
夕焼けで空が真っ赤っかになった。
The sky turned a deep, bright red at sunset.
彼
He was so embarrassed that his face was extremely flushed.
na-adjective
Used to emphasize the completeness or blatant nature of something, especially a lie. Stronger and more colloquial than 真っ赤 in this sense.
See also: 真っ赤 (まっか)
それは真っ赤っかな嘘だ。
That's a downright lie.
真っ赤 is the standard form meaning 'bright red' or 'flushed', and can also mean 'downright' (lie). 真っ赤っか is an emphatic, colloquial variant with a stronger, more vivid nuance.
Emphatic reduplication of 真っ赤 (まっか), with the final syllable reduplicated for intensification. The exact derivation is uncertain, but it follows a common colloquial pattern of emphatic repetition.