Roblox image labels not updating?

When I try collect the badge the image label is suppost to turn green after you get it here is a video showing the bug here is the code that turns the label green

script.Parent.Touched:Connect(function(hit)
	local player = hit.Parent:FindFirstChild("Humanoid")
	if player then
		game.StarterGui.Waters.Frame.HydroWater["Hydro water"].BackgroundColor3 = Color3.new(0.34902, 1, 0)
	end
end)

Your player variable is actually grabbing the character. With the character you can get the player and access their Gui information.

local Players = game:GetService("Players")
part.Touched:Connect(function(hit)
    local character = hit.Parent:FindFirstChild("Humanoid")
    if character then
        local player = Players:GetPlayerFromCharacter(character) -- getting the player
        if player then
            player.PlayerGui.Waters.Frame.HydroWater["Hydro water"].BackgroundColor3 = Color3.new(0.34902, 1, 0)
        end
    end
end)