Am I typing false value?

I'm a scripter starting out, so I thought to watch a Roblox tutorial on youtube to get the basics down. After watching, I tried to make a function of my own called Purplefy. The command I added to it is in the following:

local function Purplefy(part) part.BrickColor = Dark indigo end

Apparently, the script failed. Am I calling a false value? If I am, what would be the right one?

Make sure you understand the basics before going into functions. As I can see from your code, you don't understand data types and BrickColors.

...and here's a fixed version of your script.

local function Purplefy(part) 
	part.BrickColor = BrickColor.new("Dark indigo") 
end