[dogscoff]

but how in the heck did you figure out what color storm blocked what scan?

A list of the nebula colours was posted here a few years ago. I seem to remember that the yellow and brown nebulae cloak at level 1 and 2 (not sure which is which though). Green cloaks at level 3, then red and purple provide the highest level of cloaking at 4 & 5 respectively. I could be wrong though, and of course those pesky new "multicoloured" nebulae were introduced with Gold.

Oh, and on enemy-created warp points, Fyron forgot to point out that you don't need a presence in an affected system to spot a new warp point- as long as that system is not unexplored (ie is explored) for you, you will see the new warp point whenever you click that system on the map, whether you have a ship there or not. You may or may not get a message in your turn log about it new warp points as well, i can't remember.