I am a beginner to indesign and can't work out why when I print my document onto an A4 sheet my background colour won't go to the edge of the page. My document when printed has an uneven white border (thicker at the bottom and thin on the sides and top). Even when I choose the print option (borderless A4) it still has an inch thick white border at the bottom. I don't mind if there is a border, I just want it even on all 4 sides or not one at all.
If you are printing your document on a regular laser printer (either color or b/w) this is absolutely normal. Laser printers do not have the capability to print to the very edge of the paper sheet - there is always around 4 mm of unprintable margin along each edge (actual margins vary from printer to printer).
However, many inkjet printers do have this capability, but it has to be switched on manually in the printer settings (off by default).