Python How voxel in Matplotlib draws colors according to different values of voxels

I generated a 646464 tensor from a semantic vector using the convolution method. and plotted this cube using the Voxel function in Matplotlib. How can I draw the color of this cube based on the different values in this 3D tensor? (grayscale). Thank you for taking the time to answer my question! Add inline images

A picture of the resulting cube