I tried taking a few phone photos to understand my undertone before changing my hair color. The same face looks warmer by a window in the evening and cooler under a bright bathroom light. The shifting colors make a neat online result hard to trust on its own. I am starting with light brown hair and only want a modest shift in tone. I found skin tone analysis while looking for a way to compare images, but I still need a sensible way to use the information. The real goal is a wearable shade in everyday light, not a perfect match to one edited image. I can take pictures with the same plain background, no beauty filter, and my hair pulled away from my face. Would indirect daylight and a neutral shirt make comparisons more consistent? I am also thinking of holding a few fabric colors near my face rather than deciding from a single photograph. A stylist could then compare actual hair swatches against my skin and natural roots. That would give us something concrete to discuss instead of trying to prove that an app assigned the right season. I would keep the comparison photos unedited so the colors are easier to judge. What practical check helped you when photos pointed toward different undertones?