[SDPhantom]

While conflicts with other addons can happen, it appears not all UnitFrames are running the event-based hook that I used. I changed the hook to come in from a different approach that should run more reliably.

hooksecurefunc("TextStatusBar_UpdateTextStringWithValues",function(bar,text,val,min,max)
    local name=bar:GetName();
    if name and name:find("HealthBar$") then
        local pcnt=val/max;
        local r,g,b=1,0,0;--    Default red for both bar and text
 
        if pcnt>0.3 then r,g,b=0,1,0; end--  Green bar if >30%
        if not bar.disconnected and not bar.lockColor then bar:SetStatusBarColor(r,g,b); end
 
        if pcnt>0.3 or pcnt<=0 then r,g,b=1,1,1; end--    White text if dead or >30%
        if bar.LeftText then bar.LeftText:SetTextColor(r,g,b); end
        if bar.RightText then bar.RightText:SetTextColor(r,g,b); end
        text:SetTextColor(r,g,b);
    end
end);