Thank you for the inquiry @dlj19220301!
Color values from a colorized Lidar point cloud only carry information for the particular 3D point they represent. Since the mesh is a continuous surface, images are essential to texture it with high fidelity. Imagery and Lidar from the same system can complement each other to generate robust geometry, specially from calibrated hybrid systems (Lidar + camera). This use case is not available in Reality Studio currently, but it is in its roadmap.
I can also suggest posting your thoughts as an idea in ArcGIS Reality Studio Ideas - Esri Community.
I hope you find this information useful!
Best,
Camilo