I have my monitors set fairly dim, about 120cd/m^2. This is what most colorspaces expect the whitepoint to be, but it is very dim compared to the maximum amount of light a monitor can put out. It is about 12/100 on my monitor.
https://hub.displaycal.net/forums/topic/what-monitor-brightn...
Anyway, my point here is that #ffffff is not any sort of color you can see, merely a number that represents the maximum possible amount of red, green, and blue. If that's too much light, you can turn it down. You can also play with gamma curves to change the relative intensities down to pure black. Some people use 2.2 in dark rooms and 2.4 for "normal" indoor illumination.
example: https://raw.githubusercontent.com/ChrisKempson/Tomorrow-Them...
JetBrains compatible version: https://github.com/chriskempson/tomorrow-theme/tree/master/J...