I made this timecyc because in my opinion, the weather and colors of GTA IV were fine. I know you might argue their not that realistic, but it's how Rockstar inteded them to look. The problem is they included a "Color Correction" in the game that added a disgusting looking filter over the game. It's more apparent in The Lost and Damned, and you may know it as the "Piss Filter."
A lot of timecyc mods edit the weather colors and everything while fixing the filter and saturation - but my goal here was to keep the look IV was supposed to have, minus the gimmicky filter and lack of colors.
IV has some green-gray filter over it, TLAD has a yellow filter over it, and I think The Ballad of Gay Tony removed it, but puts emphasis on pinks and purples with the weather.
Regardless, this timecyc removes that filter. I used IV's timecyc as the base edit since it's colors are more equalized. The problem was the filter, and the lack of saturation (no colors, almost black, white, and shades of gray).
So, I removed that filter, and I increased Desatuartion to about 0.85. By default, it's around 0.60, where on the darker weathers like Cloudy or Foggy it was around 0.30 - which made IV look like an old black-and-white noire film. But for all weathers it is around 0.85, where yellows are actually yellow - but things are NOT over-saturated.
Tl;dr: Default weather colors, no gray-green filter, and saturation is fixed.
Since v1.1 I have made my own timecyclemodifiers.dat files. Just like with the timecyc, I have fixed the saturation and removed the ugly filter. Interiors have the lighting and colors Rockstar intended, along with the fixed colors and removed filter.
I'll throw together a comparison video sometime.