local function rainbowText(text)
        -- define the colors we want in the order we want them to appear.
        -- in this case, roygbv
        local _colors = {
                colors.red,
                colors.orange,
                colors.yellow,
                colors.green,
                colors.blue,
                colors.purple
        }

        -- go through all of the letters of text
        for i=1, #text do
                local char = text:sub(i,i)
                -- set the text color to the first color in our _colors table
                term.setTextColor(_colors[1])
                -- then write the character
                write(char)
                -- send the first color of our _colors table to the end
                -- we've already used it, so we move on to the next one.
                table.insert(_colors, table.remove(_colors, 1))
        end
end

rainbowText("Welcome to my room, niggas")