Diamine Bach. Last month was Mozart’s birthday, so I did a one minute ink review of Diamine Mozart ink, here. Bach is another ink from Diamine’s music set, and another lovely dark reddish brown. Bach, the ink, is darker than Mozart.
An everyday ink? Yes, it could be, for me. I love a dark brown.
Here is a comparison with Bach on the left and Mozart on the right. When you put them in the same pen, they look very close in color. Sometimes I can hardly tell them apart.