It’s one thing to see a photo and like someone’s hair color in a photo at the beach and another when you see the same person inside the office. Light changes everything so when you are choosing or even thinking about hair color it’s important that the images you see are realistic to your goals.
If it’s afternoon winter sun, the hair looks warmer, if it’s inside typically will look cooler. Direct sin will reflect warmer tones and of course then you have the fact that images online most likely have been edited slightly if not a lot!
Get your hair references ready and then once you have, go through them and cut the ones out that are second choices, then you will have a more accurate idea of the hair you want!