Most home and office printers are just not capable of printing edge-to-edge. If your printer can do it, its somewhere in the printer settings. If not, your only choice is to trim it, or live with it.
Unless your printer is capable of "borderless" printing, (and most aren't), you can't do much about it. If you need full bleed, the way to get that is to print the background larger than the finished size of the page, then trim it down to that finished size.
Thank you. My printer is not capable pf borderless printing. I think I will print it at any print shop.
Most print shops won't be able to help with borderless printing.
Toner based digital printers and copiers cannot print borderless.
If they have inkjet printers, they are usually for printing large items like banners.
Some print shops might have smaller "fine art" inkjet printers.
But their inkjet printers will be using a wide variety of media, and will charge accordingly. Some may charge by the square foot.
You need to rethink this. Assuming your document is 8.5 x11 inches, you can just print it yourself and cut away the white border.
Or if you need the color to extend to the edges of a letter sized page, you need to create the document with a bleed on all four sizes and extend all color elements into this bleed area. The bleed is usually .125 in (1/8 in) then export it as a PDF with bleeds and crop marks.
The print shop can print this letter size (with bleeds = 8.75 x 11.25 in) on a 11 x 17 in paper and they can cut away the bleeds after printing.
But they will charge you for a 11x17 print (usually double the price of a 8.5 x11 print)
They will also charge for cutting/trimming away the bleed and excess paper.