The internet is a great source to find your info and or to shop but it can also be very misleading.
Problem #1 is your screen & color settings/ability . But after all, a dark brown ito on a picture won’t look blue when you got it in your hands. Unless they have send you the wrong one 🙂
The second problem is pictures & lightning and that can be a real tricky and misleading thing especially when it concerns the hamon of a sword.
You can make stunning (detailed) pics and make your customer really disappointed when he get in in his hands and vice versa.
I literally have a few 1000 pics here of swords and blades taken from any possible angle and with any possible light source. The results are sometimes…stunning… and so different while it’s still the same sword/blade.
In order to give you a realistic idea of how a hamon can look like i’ve looked up a few blades that were shot with a different light source. After watching them you will know exact what to expect if you consider to buy a katana at some point.
Click on the pics to get some big ass format 🙂
1. Monsteel blade – standard polish
2. Monosteel blade -standard polish
3. Folded blade – stone polish
4. Tamahagane blade – stone polish

Indoor with artificial light : Little frosty white hamon with light grey habuchi and shiney/mirror body.
5. Tamahagane blade – stone polish

Indoor with artificial lightning : no real difference between color of hamon & Ji. Habuchi appears to be kind of (dark)grey

Indoor with artifical light& flash : there seems to be no diference between the color of the ji and hamon. Only the habuchi seems to be pretty white.
Conclusion
The sexyness of a blade picture  depends big time on the lightning source & angle. So when you see a very nice picture of a ‘dark Ji with a frosty white hamon’ don’t expect that you will exactely see this (effect) when you unbox your order….