Changing color of children in model?

for i,v in pairs(game.Workspace:GetChildren()) do
                local d = false
                    if d == false then
                        d = true
                        if v:IsA("Model") then
                            for i,childs in pairs(v:GetChildren()) do
                                childs.BrickColor = BrickColor.new("Really black")
                                local fire = Instance.new("Fire",childs)
                                fire.Heat = 25
                                fire.Size = 30
                                childs.Anchored = false
                                childs:BreakJoints()
                            end
                        end
                        if v.Name ~= "Moon" and v.Name ~= "Cloud" and not v:IsA("Camera") and v.Name ~= "Terrain" and not v:IsA("Script") and not v:IsA("Sound") then
                            v.BrickColor = BrickColor.new("Really black")
                            local fire = Instance.new("Fire",v)
                            fire.Heat = 25
                            fire.Size = 30
                            v.Anchored = false
                            v:BreakJoints()
                        end
                    end
            end

I need to grab the children of a model in the workspace but every single dang time i try, it seems to stop the process of the script and i have no idea how to fix it ive tried every possible way in my head and nothing's working out and i need help