color map in 3d plot, based only on the values of the z-axis?

I have a 3-dimensional plot of a curve, based on:

     xx=0:9; yy=[-5:0 -1:-1:-4]; zz=[1:5 4:-1:0]; 
     plot3(xx,yy,zz,'-o'); 

I wish to add a surface underneath this curve, with a color map that represents the height of the curve along the z-axis. Namely, I wish that the surface will be more blue when z is small, and more red when z is high.

How do I do that? I use Matlab 2014b (unfortunately)...

Thanks!