It's usually bright red for the first few days. Think tomato ketchup. It's not all blood even though it looks like it, or it would be a clot.
After the first few days, the red blood cells which had leaked out break down, and the bright red iron oxide which was in their hemoglobin turns into rust (a different iron oxide) and hence the bright red turns brown (it literally is rust). This is a bruise (leaked blood). Any presence of bright red after a few days means new bleeding, whereas brown means it's from old bleeding.
If you don't ejaculate for many weeks, you can find your semen is black by the time you do.
We get very worried calls on the helplines for red/blown/black semen. The hospital leaflets are woefully inadequate in setting expectations.
It is worth trying to get it out. Your body will try to break down and reabsorb the leaked blood/bruise, but with the amount in the prostate after a biopsy, it won't usually manage to do it that way. This can leave you with literally rust in your prostate. This is magnetic, and it can interfere with future MRI scans, and prevent getting high resolution images of your prostate, e.g. due to later recurrence. So it is worth trying to ejaculate it too. If you are on hormone therapy already, you might find you can't ejaculate the blood.