I have exclusively used Rajasthani henna from HennaSooq for the past few years. I do a 70/30 blend with Indigo (also HennaSooq), with a 4 hour henna bloom prior to mixing in Indigo. The dye sits for another 4 hours.
I consistently achieve a beautiful, warm brown with subtle red highlights. It relaxes my curl pattern (2c/3a) by about 25%.
I have naturally warm brown hair and most people are surprised to learn that I've begun using henna to dye my "Covid-stress" white hairs. You can achieve accurate natural color through this process.
This particular henna definitely skews "warm tone", IMO.