10 miles below 20,000 and 20 miles above, preference up-wind. Another company same, but also had no approach to land if cell within 3 miles of RW and moving towards approach path. I have always taken this sort of thing as a guide, once again, common sense, local knowledge, experience etc etc. There are storms and there are storms. I always think some of the tropical beasts look worse than what they are and some of the little ones attatched to a cold front in cooler climates can beat you to death. I've had hail in clear air by being a little close. Must know the radar and how to use it, listened to a guy a few months ago going around "weather" on a clear night over Afganistan, he was going around terrain as far as I could make out. As for colour, even the green bits above 30,000 will put waves in your coffee.