I have been attempting a simple undertone check with my phone, but the result changes every time I move rooms. The screen brightness seem to change the apparent balance of my skin much more than I expected. I now plan to take several photos near the same window on separate days. I am keeping makeup, filters, and automatic colour effects out of the process. Rather than treating one picture as proof I would compare a few neutral fabrics beside my face. Muted teal, rose, graphite, and soft white would give me more than one clue to consider. I am planning to note whether each shade makes shadows, redness, or unevenness more noticeable. I will review the pictures later instead of judging them immediately. For a basic framework, I am consulting <a href=https://faceshapeanalysis.top>skin undertone test camera</a> Has anyone found a simple setup that stays reliable across different days?