Las files do not contain true color information. Therefore, when you import a las file directly into CloudCompare, you will only see a pure white point cloud.
If you want to assign colors to the point cloud without true color information, you can try the following methods:
1. Photo-texturing: You can take a series of photos for the point cloud and match them with the point cloud. In CloudCompare, you can use the photo-texturing function to project the colors from the photos onto the point cloud, giving it true colors.
2. Feature-based coloring: If you don't have photos or cannot match them with the point cloud, you can use feature-based coloring methods. This method analyzes geometric features (such as normal directions, curvature, etc.) in the point cloud data to generate pseudocolored representations. In CloudCompare, you can use tools like the Rainbow Colorizer or similar methods for feature-based coloring.
Please note that assigning true colors to a point cloud requires additional data or feature analysis, and may not be applicable to all types of point clouds. The specific method to use depends on your data and requirements. I hope this information answers your question.