Problem with tables?

What are tables?

Tables are basically dictionaries for Lua. Tables can be called either like:

local exampletable = {"I think I'm pretty", "I think I'm codey", "I think I'm helpy"}

Or like:

local exampletable = {
"I think tables are cool",
"I think tables are useful",
"I think tables are helpy"}

For your case, you will just want to put the BrickColor names as strings. Here, I'll fix your table code:

local Colors = {
"Lime green",
"Hot pink"}

What is BrickColor?

BrickColor is a constructor used in changing colors of Parts. To change it, you must do it as such:

script.Parent.BrickColor = BrickColor.new("Lime green")

But you want to implement a random color. So you would use math.random() to pick a random color out of your table. But how do we access contents of a table? Using the # operator. Yes, we are going to start a fanbase of #Colors. To implement this random color picker, just do this:

script.Parent.BrickColor = BrickColor.new(math.random(1, #Colors))

This is just a simple way of picking colors out from a table. If you want full randomness, you can use Color3.

script.Parent.BrickColor = Color3.new(math.random(1, 255) / 255, math.random(1, 255) / 255, math.random(1, 255) / 255)

This code will give you a completely random color.