Lately I have discovered dark brown ejaculate, where in the past it was the standard light straw color. Why is this?

Are you sure it's brown and not a deep red? I have never heard of brown ejaculat. Have you had anal sex recently without using a barrier method? Have you changed your diet? This last question is especially important because your diet can affect your semen.

Some possibilities below from Malehealth : Sexual Problems - Ejaculation and Semen and big change in color of ejaculate - Sexually Transmitted Disease (STD) Forum.

Brown coloured stuff in semen

Q. I recently masterbbated and when I ejaculated there was some brown colored stuff in with my semen. Is there something wrong or does this happen occasionally?

A. The colour of semen does change as does its texture. Generally speaking however it should be pearly white not dissimilar to raw egg white. Old blood turns brown and you may have suffered from a blow to the testicles earlier on. Badly designed bicycle saddles on mountain bikes are a prime suspect. You could also have suffered an infection which can cause slight bleeding into the semen.

Prostatitis, inflammation of the prostate or an enlarged prostate can also bleed although the blood is generally red in colour. Finally testicular cancer can make its presence felt in this way so it makes sense to get it checked by your own doctor sooner rather than later.

Question: Two days ago I was stunned to see my ejaculate was brownish - it looked like thick saliva with a little coffee in it. It was the same way today. I have no history of stds, have been with one person for 3+ years, suffered no recent injuries (anywhere on my body) and have never seen anything like this before. No pain, no burning, etc. please help me understand what's going on.

Answer: Probably not an STD. Brown semen usually means blood, but it happens from time to time in many men. The medical term is hematospermia. Sometimes it can be triggered by trauma to the perineum--the space between the scrotum and anus--for example, after a bike ride, horseback riding, etc. But many cases are spontaneous. If there are no other symptoms, such as discharge from the penis or pain on urination, just sit tight (no pun intended!); if it goes away over a few days, don't worry about it. But see a health care provider if the discoloration continues after several ejaculations or if it keeps coming back.