If you want to step more away from that sweet, Negroni-like profile, and for an extra layer of flavor, I'd suggest splitting the red bitter liqueur to allow for that darker taste of coffee liqueur. So try 3/4 oz red bitter liqueur and 1/4 oz coffee liqueur.
Very refreshing, but if you want to elevate it just a bit, try adding a barspoon of herbal liqueur (I used Shaman by Sivo) and maybe even a barspoon of Midori for a touch of color. Garnished with a sprig of fresh bush basil.