Is this a problem outdoors at night, as well?
Try lowering the game resolution, and see if that makes a difference.
Try the
Windows 8 Performance "Patch" (works in Win 7 and 10, as well); that can help with some graphics issues.
In the Divine Divinity install folder, edit the config.div file (in Notepad, or other text editor) and add/edit the line 'rgb 555' and change the number to something else, like 565. If the line isn't there, go into the graphics options and change the gamma, or something, and it should be added, or you can do so manually (just not as the last line in the file, as the game expects that line to be blank, and ignores it).
Try using the disk version of the configuration program, to set the game to run in Direct Draw mode. Rename or move the existing configtool.exe and NlsEng.dll files in the install folder, and extract the disk versions from
this zip file.
Note that this will reset the game resolution to what the disk version supported, but you can manually change it back by editing the config.div file.
You could also
try WineD3D, rather than Direct3D
Graphical Issue, Indoor textures turning black?Software/Direct 3D Issues
