Which fountain pen ink do you use?

A recent HN thread (https://news.ycombinator.com/item?id=39301948) got me thinking that I should try other inks. I use a fountain pen as my daily driver (Lamy Safari and now trying the Lamy CP1) but I haven’t ventured beyond the tried and tested inks. Growing up, I used Camlin Royal Blue (I grew up in India). I currently use Lamy ink cartridges, which work well, but don’t have the breadth of colors available in the fountain pen universe. So, please help me with recommendations of inks (colors and brands) I should try to enhance my experience.