Have you tried All Natural with its Natural Interiors and Real Lights? Those mods in that package work well with AWLS (Advanced Windows Lightning System). Windows light up from outside when it is dark depending on weather or time and with individual settings for each city (take some time to use Wizard in WB instead of picking one setting for all of Tamriel) this make it feel more realistic. AWLS do also add smoke from chimney, which adds to the feeling of a more vivid world. Real lights adds more realistic light sources like candle which actually look more alive, caves and outdoor have also another colour (depending on what one set up). Caves look much darker which make light sources like torches and candles stand out more, but it can also become a bit too dark to actually enjoy explore those dark places for several hours, so I "cheat" with Night-Eyes. There is also street lights in different places in cities and with Immersive Interior you have a more realistic view from windows. Immersive Interiors is a series of mods where those mods make it possible to look out of windows from inside and look outside with some limitation described in mods documentation. In some buildings you can see that they had to "close" that windows as it wasn't possible to create a realistic view as there was another building right behind etc, so in some places it will not look the same as vanilla Oblivion, but they have put a lot of effort to make those windows that show outdoor as much as possible. All Natural is also a weather mod which make it so you can see flashes when you are indoor during thunderstorm, hear rain while you are inside etc. All Natural and all those mods I mention have pretty good instruction for how to use Wrye Bash to install. Especially Bashed Patch is needed for importing cells (tweak) and to merge some of those plug ins. I use Oblivion Reloaded version 5 (no ENB) and have tweaked its colour setting among other, so it might be that you need to play around a bit with settings in OR or ENB if you use that to get the best mix from All Natural's colour and those two mods. There are some threshold where black look too dark (unnatural) and lights sources start too look odd. In OR you can enable/disable settings on screen, so it is possible to adjust settings on the fly. Don't forget to adjust settings on your monitor as you have both gamma there, in OR and in Oblivion as an example of at least three places where you can find the same setting.