How do you separate close seasonal palettes?

My latest colour-season question is about Deep Summer versus Soft Winter at home. Similar cool shades begin to overlap when I compare them in person. I first set up a small comparison in indirect daylight. The comparison felt fairer after I removed obvious colour distractions. I noticed that richer colours looked striking while sometimes emphasising tired shadows. Dustier cool colours looked harmonious, although preference can easily distort a test. Rather than naming a season first, I noted contrast, texture, and eye clarity. A structured color analysis would be useful as a second checklist alongside the fabric photographs. I see online tools as prompts for observation, not as final proof. What practical comparison made adjacent cool seasons easier to separate for you? I would especially value methods that still work on an overcast day. A small, repeatable process feels more useful than chasing a perfect label immediately. Repeated observations across ordinary days should be more useful than one flattering photograph. Thanks in advance for examples of what you found genuinely repeatable.