I want to use photos for blog. Nature, landscapes, fitnes. I use photos which have 16,7 Million color variations (24 BitsPerPixel) now.
Is it possible to use photos which have color depth more than 16,7 Million color variations (24 BitsPerPixel)?
The short answer is: no, the maximum practical color depth for images on websites is 24-bit color. Few image formats support higher color depth (TIFF is a notable example), and of those, there are none that all common web browsers support.
Wikipedia features a table of web browsers and the image formats they support. You can see that Chrome and Firefox - which account for about two thirds of browsing - do not support TIFF, although Safari and Edge do. Unfortunately, even if you created a reliable mechanism to serve TIFF files to browsers that support them and JPEG to the rest, your TIFF files would only be seen by a third of visitors.
Aside from browser support, there's another limitation: many people don't have display systems that can render more than 16.7 million colors. This isn't just a function of the monitor, since the graphics card must also support higher color depth. These are both more expensive and specialized items that most don't have on their desks at home.
Ultimately, even if browser support for deeper color increases, there will need to be a massive change in hardware standards before it will become widely accessible.