Do black specs(like tiny pepper flakes) in the stool indicate blood even when the stool in a normal brown color?

Nah: Significant blood loss (more than 3-4 ounces of blood), especially from upper sources, e.g. Stomach, duodenum , small bowel, less likely from right colon, can give black, tarry stol, with a typically characteristic odor, often loose (blood is a laxative):melena (black). Entire stool would be black, not just individual spots. Likely from food, seeds. Iron pills, pepto bismol (bismuth subsalicylate) can do also.

Get tested: If you have any doubt, you can get tested for blood in stool. Guiac test can pick up bleeding from anywhere from the mouth to the other end.