Where can I find last "blue screen" error message after reboot in Windows 10?

Just saw a "blue screen" in Windows 10. I wanted to google the error message but the moment I reached the phone to take a photo - computer rebooted.

Can I find this error message somewhere in the logs?

Yes, it's recorded in the Event Log. I quote the bsod tag wiki:

If you didn't catch the BSOD display, information about the crash can be found in in System event log (viewable in the Event Viewer, eventvwr.msc). Error events from the BugCheck source contain the bugcheck code, the parameters, and the path to the dump file on the General tab. Critical events from the Kernel-Power source contain the code and parameters in the EventData section of the Details tab.

For a list of all possible BSOD errors and their descriptions, see the Bug Check Code Reference.

Once you get the numeric bugcheck code as a hexadecimal number, you can consult that reference to find its symbolic name.