Sadly, I too, am in the red/green color vision issue boat. I can see red and I can see green just fine under most circumstances. But sometimes when they are put next to each other, they blend in. Its more of a lighting or shade issue I would say. However, being a hard core bow hunter for many years, not being able to see blood on the ground most of the time has its challenges.
With that said, I will convey this, and please do not beat me up for stating this.
Due to blood tracking issues for so many years now, I have learned how to read the woods much better. For ways and reasons I cannot understand, much of the time I can see where a hit deer traveled when others do not see a thing. Its almost as if I can see their tracks when none can be seen by others. Sometimes I can walk in places I have never been before and see where deer have walked even if they are not on a path and the leaves have covered up their tracks. This has become obvious time and time again when I had others help trying to find a downed critter. And if I cannot see their tracks or blood, its as if I can know what direction they went anyway. Weird I know, but its true. To be clear, this does not always happen, but much of the time it does. I have killed over 60 deer with arrows and the only way I found many of them, much of the time was by reading the woods and walking where I was sure they went.
This pretty much happens in woods only. Open areas and/or fields are a different story. That's where I have those real "they Lord have mercy" moments.