How do you use [] with math.random?

Im scripting something that HAS to be randomly generated in a table But I dont know how to randomly generate it, without using math.random, And I dont know how to use math.random, Any Examples???

EDIT 1

I want a Brick To change Colors In a Pattern Like a Wave But Randomly generated I need to know how to use [] and math.random to generate a random color in a brick.

Colors = {"Bright blue","Bright red"}

interval = 1

while wait(interval) do
script.Parent.BrickColor = BrickColor.new(Colors[math.random(1,#Colors)])
end

There! Put real colors where the "Colors" table is If you don't want to set it do this:

interval = 1

while wait(interval) do
script.Parent.BrickColor = BrickColor.Random
end