he is referring to the seed casing. some are dark brown some light brown, some are mottled (or striped). the stripes have nothing to do with whether the seed is ready or not. if a seed is green or very light brown or even grey they are usually under-developed. dark or mottled seeds are more developed and show higher germination rates.
as for the glass of water, i never pre-soak my seeds. i just fold a paper towel in half then half again. place my seeds inside, run them under tap water long enough to get the paper towel wet, then into a quart ziploc and onto my dvr/cable box. check back in 24-48hrs then i'm in business.