[Xrystal]

That is a good point. I totally forgot it didn't have a height either.

But, I somehow managed to get things to work again as a status bar.

Can't think what is different outside of using a different texture. Instead of setting BarTexture in the xml to an atlas ( example from one of the blizzard files) , I used SetStatusBarTexture with the texture used in the example here ( https://warcraft.wiki.gg/wiki/UIOBJECT_StatusBar ).

I changed the following in ApplyLayout after changing the Frame to StatusBar in the xml and removing the alternative bar texture section.

-- Set up the BarTexture Position
    --newFrame.Bar:ClearAllPoints()
    --newFrame.Bar:SetPoint("LEFT",newFrame,"LEFT",0,0)
    --newFrame.Bar:SetWidth(50)
    
    newFrame:SetStatusBarTexture("Interface/TargetingFrame/UI-StatusBar")
    newFrame:SetStatusBarColor(0, 1, 0)
    newFrame:SetMinMaxValues(0, 1)
    newFrame:SetValue(0)

And the following in UpdateBarTexture

--unitFrame.HealthBar.Bar:SetWidth(offset * activeLayout.width)
    --unitFrame.HealthBar.Bar:SetColorTexture(r,g,b,1)    
    
    unitFrame.HealthBar:SetStatusBarColor(r,g,b)
    unitFrame.HealthBar:SetMinMaxValues(0, maxHealth)
    unitFrame.HealthBar:SetValue(health)

The bar is shrinking and the color is changing as expected. Thanks for the reminder though.