You are welcome,
I have checked the screenshots of the program Wavepad and for Mac and this image you shared with us is no published in the web page. However, it is not strange that the file is still in our web server as some web masters will leave them in the server if the could be used in the future and maybe they forgot to delete it. I apologize for that inconvenience.
I have also installed the version of the program in which these screenshots where captured to check if whether or not there was an option to change the color of the spectrum. Unfortunately it seems to be that the color was added to emphasize the difference in the graph.
in the future; you can contact us via our support page http://www.nch.com.au/support/index.html email support is free of charge and our response time is within 24 to 48 hours.