fake blood store

How do I put fake blood on clothes?
I need to put some store bought blood on my costume, but I don’t know how to make it look real. Also, I’m not sure if it will be dark enough. It’s going on a white shirt, should I try to darken it with something or do you think it will be fine? I only have one tube.
Put the shirt on and pull it up, then put cling wrap on your skin so the access blood won’t absorb into your skin, then whilst laying down (so it doesn’t drip) put a glob of fake blood down, then pull down your shirt and let it soak through (or press down) like a real wound. To make it darker mix a drop or two of green food coloring into it, green darkens reds because they are complimentary colors.
Miniature Tigers-Last Nights fake blood