When we want professional printing with color right to the edge, we must include bleed margins. Printing services don't actually print to the edge. They trim off the white margins so it looks like the color goes right to the edge.
Let's say we want 100 color prints of our 8.5 x 11 flyer. To produce this, the printing service needs us to submit a PDF that is 8.75 x 11.25 because this includes bleed margins which will get trimmed off.
Create a custom paper stock:
Start a new project using this stock. Add your images and text. Imagine a safety zone (indicated in green here) where everything outside the safety zone gets trimmed off. That will help you keep text well away from the edge. Adjust your photos so important parts stay within the safety zone.
Save your project as PDF, 600 dpi resolution. This new PDF is ready to be submitted to your printing service.