I have a pause of 3 because I am using an external clock signal from a 555 astable with an adjustable (low) frequency ( so that the flash rate is adjustable). It is definately a visible speed. The colons are there because I had each sequence on it's own line earlier. I split the lines and left the colon's because I read something last night in an old post by ski-mask discussing something along these lines. I just recoded without the colons as I'm typing this and nothing changed at all.