Rainbow Text Function Adapted

--[[Function Adapted]]--
local roygbiv = {
  colours.red,
  colours.orange,
  colours.yellow,
  colours.lime,
  colours.lightBlue,
  colours.blue,
  colours.purple
}

local function rainbow(text)
  local num = 1
  for i = 1,#text do
    local letter = string.sub(text,i,i)
    if num > #roygbiv then num = 1 end
    term.setTextColour(roygbiv[num])
    term.write(letter)
    num = num+1
  end
end