How to show gmx spatial output as a colourmap (heat map)?

Dear GMX users:

I have used gmx densmap to have a 2D density map in GROMACS. Now, I want to study a 3D density map of water in a Water/Zeolite system. I used gmx spatial to see it in VMD. First, I want to know if this is a true way or not? Second, the isosurface option shows dots in just one color in VMD. But I want to see it as a color map ( e.g., blue to red). What should I do about that? I have attached two screenshots for 2D colorful density map and from VMD for 3D density map here in this discussion.
Thanks in advance