expression, godan verb (-ru)
be covered in blood; welter in blood
Literary or dramatic expression for being drenched or stained with blood, often in battle or violent scenes.
戦場は朱に染まった。
The battlefield was stained red with blood.
expression, godan verb (-ru)
turn red; become crimson
Used for something turning a vivid red, such as the sky at sunset or autumn leaves. Less common than the blood sense.
夕焼けで空が朱に染まった。
The sky turned crimson in the sunset.