顔が赤く

face turns red

→ 顔
phrase Rare #37,861
face turns red Usually followed by なる, as in 顔が赤くなる, meaning that someone's face becomes red or they blush. The form 赤く connects 赤い to the following verb.
JA: 人前で話すと、すぐ顔が赤くなる。
EN: When I speak in front of people, my face immediately turns red.

彼は彼女を見ると顔が赤くなった

He blushed when he saw her.

私は恥ずかしくて顔が赤くなった

I was embarrassed and my face turned red.

真剣な顔が赤くなってる

Your serious face is turning red.

— タイタニック (1997)

考えるだけで顔が赤くなっちゃう

Just thinking about it makes me blush.