A comment on the document's design: The low contrast of light gray text on yellow background makes it difficult to read. Black text on white, or dark gray text on white is perfectly acceptable.
Another drawback of colored backgrounds is that readers wanting to print out the pdf will consume ink/toner to render the non-white background.
That site is great but it leaves out something else that is very important. Color blind people often have trouble with seeing colors that are "near" to each other in color-space.
I'm not a PhD in Colorology but choosing higher contrast colors completely eliminates that problem I think. It's an easy fix that opens up many new markets to your software.
Another drawback of colored backgrounds is that readers wanting to print out the pdf will consume ink/toner to render the non-white background.