Is there a reason on why this health.Changed script won't work?

wait(game.Lighting.TimeToLoad.Value)

-- Health Bar
local HealthB = script.Parent.bk.HBar

repeat until game.Players.LocalPlayer.CharacterAdded:Wait()

game.Players.LocalPlayer.Character.Humanoid:GetPropertyChangedSignal("Health"):Connect(function()
    local redzone = game.Players.LocalPlayer.Character.Humanoid.MaxHealth / 2
    if game.Players.LocalPlayer.Character.Humanoid.Health <= redzone then
        HealthB.ImageColor3 = Color3.new(255, 0, 0)
    end
    if game.Players.LocalPlayer.Character.Humanoid.Health > redzone then
        local brickcolor = BrickColor.new("Lime green")
        local color = brickcolor.Color
        HealthB.ImageColor3 = color
    end
    HealthB.Size = UDim2.new(game.Players.LocalPlayer.Character.Humanoid.Health / game.Players.LocalPlayer.Character.Humanoid.MaxHealth, 0, 0, 20)
end)