Deep Winter or Deep Summer: what helped you decide?

EllaType

I have been comparing my undertone in photos but my results change more than I expected. Near a north-facing window my skin looks fairly neutral while warm indoor bulbs make it look noticeably golden. The camera appears to correct color on its own even when I keep the same position and background. I kept my face bare and wore a medium-gray shirt so clothing should not be adding much reflected color. I am comparing the photos with a simple skin undertone test camera rather than trusting one image. Should I disable portrait mode and lock white balance before taking a short series of photos? I could place a white sheet and a gray reference beside my face if that makes the comparison more useful. For anyone who has compared camera tests with an in-person result, which lighting conditions were consistent, and which clues did you ignore? A repeatable checklist would help more than a single verdict before I start choosing hair or clothing colors from the result.