TweenPartDemo

-- Services
local TweenService = game:GetService("TweenService")

-- The first parameter of TweenService:Create is the instance we want to tween,
-- in this case the part, so let's create a variable for it
local part = script.Parent

-- The second parameter is TweenInfo. This is a datatype created in a similar
-- way to Vector3s, using TweenInfo.new.

local info = TweenInfo.new(
    1, -- The time we want the tween to last
    Enum.EasingStyle.Linear, -- The style we want the tween to play in
    Enum.EasingDirection.InOut,-- I don't know how to describe this
    4, -- The amount of times we want the tween to repeat
    true, -- Whether we want the tween to reverse when it's done playing or not
    0.4 -- The delay time in between each repetition of the tween
)

-- The third parameter would be the properties that you want to change, and the
-- values you want them to be at by the end of the tween

local properties = {
    Color = Color3.new(1, 0, 0)
}

-- Now, we will call TweenService:Create, and it will return (give back) a Tween object
local tween = TweenService:Create(
    part,
    info,
    properties
)

-- Hold on! The tween isn't playing just yet. We need to call tween:Play to make it run.
tween:Play()