Lack of a better way to say, "Can I make it so that I can pick and choose which stains should be able to appear?"

I like dirt and blast scorching my gun over time but the blood overtakes the entire spectacle and is the most rapidly-collected because of how much you can get shot. Every time you get shot you bleed all over your gun. Meanwhile I still want zombie green blood to appear when blowing a headcrap off at point blank.

I tried adjusting the scales but it didn't do anything.

Maybe a tickbox of which decals can appear? Would appreciate it.