IPL Settings Suggested For Light Pigmentation Therapy On Face?

You cannot  get the right answer without knowing the exact brand and version of laser / IPL that is being used. If anyone gives you a response with a Joule setting , please disregard. All filters , power , energy , spot sizes etc make the difference with lasers so no one can answer your question right now safely. you are right that settings need to be adjusted for skin type and issue being treated. Be sure a dermatologist reviews your settings before being used 

None of us can answer this question for you because IPL settings are specific to each type of machine. Additionally, some machines have additional settings to consider, so even though sometimes the joules may be lower another type of energy in the machine is higher, which raises the strength of the IPL being done. So, frankly, we can't tell you and you'll need to just make sure you go to a qualified office with a physician whose staff is well-trained.