How to make damage popups? (using Yanfly)

[Varkarrus]

Hey, so I was working on an Execution Damage plugin. The idea there is that a skill with an Execution tag would fail to deal damage if it wasnt enough to instantly kill the target.

    if (this.isExecution()) {
    if (value < target.hp){
        value=0;
        target._result.hpAffected = false;
        }
    else{
        target.setHp(0);
    }
    }

It works just fine! I'm kinda surprised that there weren't any errors, and I made a skill with an execution tag just fine.

It's just, I want to fix up the damage popups to make it more clear what's going on. Right now it's an Ordinary damage number on a successful kill, and a 0 on a failure. I'd like to change the color of the text on these popups, and replace the 0 with "Failed Execution"

And, what should be relevant to this, is that I'm using Yanfly's battle core plugin, which I believe does some stuff with damage popups already.