The Bloomberg Terminal [0] has been very high-density and high-contrast since its early days of being an 80x25 terminal interface. Some would say it's not the prettiest UI (although as a former employee I still have a soft spot for it) but it's incredibly functional and also unmistakeable at a distance.

[0] https://assets.bbhub.io/image/v1/resize?width=auto&type=webp...