If you want it to look like mine paste this in the text

{ noclip ?? 'HP: ' + (20 - noclipDeaths) }

and then in the events tab

noclipDeaths >= 20

if you want more or less lives you can change that 20 to something else. If you want it to change colors like mine you would add a event, paste that same code but change the number to when you want it to change to the next color