LASColor ortho offers you the ability to give color to your point cloud in LAS format using an orthoimage.
You'll need liblas in order to work with LAS files, ortoMng to manage orthoimage and PIL and Numpy (ortoMng need them for work).
ortoMng
liblas
las_easyRGB(lasFile, ortoFile, geoRefExt, lasOutput, mask):
''' function to assign color to LAS point cloud using an orthoimage Input: lasFile: LAS file name. string. full path + name + ".las". ortoFile: orthoimage file name. string. full path + name + image extension geoRefExt: type of georeference file (tfw, jgw, ...). string lasOutput: LAS file name for output. string. full path + name + ".las". mask: color used in orthoimage as a mask. If the algorithm find this color or black it'll assign intensity as point color. Output: A new LAS file will be created in lasOutput location. '''