Some IPL devices are more sophisticated than others in that there can be a variety of settings for an effective, individualized treatment, or just one setting for everyone, which will not work as well. The skill of the technician is also important. You should not be tanned before your treatment since it would change the settings that can be used. The Lumenis One is an excellent IPL device.
There are literally thousands of IPL machines on the market. Some will be minimally effective, and some will be outstanding. Additionally, the operator is also key. The machine has no ability to treat you on its own so the settings, number of pulses, type of pulses, coverage, etc. is also key. There is no universal setting to give you that is for your skin tone. Each machine will have its own way to be set, so I can't give you a concrete answer on that. But yes - both the machine type and the operator matter!
"This answer has been solicited without seeing this patient and cannot
be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."