We recently supplied files to an outside vendor for our ebooks. Usually, when done in-house all (pdf) files are converted completely to RGB.
However, when we got the pages back, the background images and objects were RGB, but the black text was in CMYK. When we asked, the vendor assured us that the text was more readable this way.
I cannot fathom the purpose of this, since it is entirely a digital book and will not be printed. Is there something that I'm missing, or are we right to be suspicious?