how to view data on a DEM-readhgt

Through the READHGT function I was able to download the DEM data of an area of interest. above this DEM I have to load the maps that I have already done so that directly on the DEM you can view the data of the maps that I want to insert.

how could I do?

also the DEM I would like to do it with grid coloring in the color scale. You can help me?

[KSSV]

What is READHGT ?

[ELISABETTA BILLOTTA]

https://www.mathworks.com/matlabcentral/fileexchange/36379-readhgt-import-download-nasa-srtm-data-files-hgt