
Fallout New Vegas has 3 rock variations from the standard Mojave rocks. These consist of Red Rock, Black Mountain, and snow covered rocks around Jacobstown. The vanilla game uses a method called vertex painting to make these rock variants have different coloring to the default rocks. While this is efficient at reducing the number of textures in the game files, it can look blotchy and visually unappealing, as well as leaving no room to control rock variation by texture. Vertex lighting is best when used to simulate ambient occlusion (like on the default rocks) because it overlays colors on top of mesh vertices. With this mod, rock variations will utilize the default rock mesh values and point to new textures not previously found in the game files. Red Rock and Black Mountain utilize all new texture files to achieve their unique look, and the snowy rocks point to operation anchorage files already included in the game. Vanilla LOD is also touched up with this mod to reduce pop-in and allow for a smoother, more consistent look.

Any mod that also replaces rock meshes is likely incompatible with this, as this mod modifies unique rock meshes to achieve it's goal. It would require a patch to apply whatever changes were made to these rock meshes too. Texture replacers for vanilla rocks are compatible with this, but likely won't cover the new texture variants unless the author has taken such into account.
Instructions

Install via mod manager or manual download buttons and utilize the manager of your choice. Mod Organizer 2 is recommended. Alternatively, install the files manually by dragging them into your games "Data" folder and activate with the mod manager of your choice.
Requirements
Improved Rock Variants
Main file.