Pulse V2

local chartbl = {"*","%","@"}
local colortbl = {colors.blue, colors.lightBlue, colors.cyan, colors.green, colors.lime, colors.yellow, colors.pink, colors.magenta, colors.purple, colors.blue}

local curCol, incCol, reverse, maxx, maxy = 1, 1, false, term.getSize()

local function advClear( c, b, t )
    term.setBackgroundColor( b )
    term.setTextColor( t )
    write( "\n" .. c:rep( maxx ) .. "\n" .. c:rep( maxx ) )
end

term.setCursorPos( 1, maxy )

while true do
    for theChar = 1, #chartbl do
        advClear( chartbl[ theChar ], colortbl[ curCol ], colortbl[ curCol + (1) ] or colortbl[ 1 ] )
        sleep( 0.05 )
    end
    for theChar = #chartbl, 1, -1 do
        advClear( chartbl[ theChar ], colortbl[ curCol + (1) ] or colortbl[ 1 ], colortbl[ curCol ]  )
        sleep( 0.05 )
    end
    curCol = curCol + 1
    if curCol == #colortbl then
        curCol = 1
    end
end