I like Bourjois liner feutre, for me this is the only eyeliner I've come across that doesn’t smudge, and I can do a very fine line without making a mess.
However, as I get older I feel black eyeliner looks a little harsh, and browns are often the wrong shade of brown to suit my skin tone.
Can you recommend a fine felt pen type eyeliner that comes in a deep or jewel tone blue/purple/green?