Is Pico Toning effective even for dull skin tones?

Lately, my face looks duller overall than before, and the skin tone feels uneven, especially around the sides of my nose and cheeks, so I am looking into Pico Toning. I don't have many very dark freckles or spots, but when viewed up close, there are areas that look like faint stains, and on days when I'm not feeling well, my whole face looks even more dull.

I've consistently used whitening and vitamin products, but I haven't really noticed much of a difference other than my skin becoming moisturized. Can I expect Pico Toning to be effective even with these concerns?

I am wondering if Pico Toning is only done when there is dark pigmentation, or if it is also frequently received by people like me whose skin is generally dull and uneven.

I would also like to know if I can see some difference after just one or two Pico Toning sessions, or if I need to undergo them consistently for several sessions to assess changes in my skin tone.