Why are phone books called "yellow pages" and/or "white pages"?

Question

why cant they just call it residential phone book or business phone book?

Answer 1

To call the white pages "residential" would not, strictly speaking, be accurate, since they are normally an alphabetical list containing both residential AND business numbers.

One or two English-speaking countries actually use slightly different terminology.  For example, in the Republic of Ireland they use the same white and yellow to distinguish between the sections (or volumes) but the yellow pages are referred to as "Golden Pages."

Answer 2

some do - but it's terminology that's been around for a long time.  depending on who is putting out the phone book - they may call it residential listings or white pages or business book or business listing or yellow pages.

Answer 3

That is because phone books used to come in one large book with both in them.  To distinguish between the two types of listings, residential and business, the colors were made different.  Also, businesses wanted to appear in a separate area to highlight their business.  Now, because the books have become so large, most are printed in two different "editions."