How reliable are virtual hair-colour previews?

My sister asked me to help with her hair-colour shortlist because she wants a modest update before her wedding. She is currently a neutral bronde, and she does not want guests to notice a sudden or theatrical change. The difficulty is that one sample looks soft and balanced indoors, so everyone reaches a different conclusion. One relative prefers a deeper root, while the photographer advised keeping the overall contrast familiar. We decided to stop voting from separate screenshots and compare the same references on one shared screen at normal brightness. Her dress is cool white, and the ceremony includes both a dim room and outdoor portraits. That combination makes the colour beside the dress more important than chasing a fashionable label. We used [url=https://best-hairstyle.top]cool summer hair colors[/url] as a place to narrow the examples. Next we will photograph two borrowed extensions in the ceremony room. The stylist can then judge whether subtle lowlights is the safest choice. We also plan to keep the camera settings fixed during the test. What is the simplest way to confirm a subtle colour before the wedding?