Madder Red
Dark Red, Crimson
noun
Red dye color is madder red, or dark red. This word is used most often to describe the color of the sky at sunset in literature.
The readings are the same as the ones you learned with the kanji.
空が夕焼けで茜色に染まっていて、とても綺麗でした。
The sky was crimson in the sunset, and it was very beautiful.
茜色の空を見ながら、シャンパンを飲んだ。
We drank champagne while looking at the madder red sky.
見て、空が燃えるような茜色になってきてるよ。
Look, the sky is turning a fiery dark red color!