Even though any blood is clearly not good in stool is it preferable for the blood to be black tar(upper gi) or red?

Interesting question: ...and one wonders why you would ask? Blood is never good in stool. But a little red blood means the problem is likely something right at the edge, like a hemorrhoid, while tarry black stool means the bleeding occurred much further up, where stomach acid could make it turn black. However, much red blood can also mean there was more than stomach could acidify, or bleed is from the intestine.