Darker seeds are usually more viable. White or light colored seeds are usually imature. Some old growers use a cup of water to determibe viability. if it floats it suppose to be a bad seed. IMO this method isn't fool proof and don't use it but I have friends who swear by it.
this is what I do. Take the seed, place them in a green dish cloth not used soak it then place warm area, open it after 24 hrs if starting to dry soak it again. seeds should be ready to plant in 2 days max
i did something like that with my last 2 seeds. i had them in a wet napkin in a bag and had nothing after about 2 days so i took the bag and put it in a dish rag in my vent for the heat in the house and they popped overnight like that