Saving a RGB numpy array into *.vtk for visualisation

Hi, i wonder if it is possible in a simple way, to save a 3D RGB (so 4D) numpy array into the *.vtk format readable by paraview. I used to work on grayscale images and this small command did the trick:

arr = np.random.rand(64, 64, 64)
arr_vtk = pv.wrap(arr)
arr_vtk.save("arr.vtk")

but for now, if i want to save this array, how can i do ?

arr = np.random.rand(64, 64, 64,3)

the 3 channels stands for the RGB channels and i would like to visualise them (the final color) using paraview if possible …
is it also possible to specify where to save the data ? (points / cells) ?

Thanks