I really think the manufacturers just aren't bothering with the color standard as far as the frequencies are concerned. It seems like for a while, cable/ant was white/clear and satellite was blue, then green, but more recently I'm seeing blue, green, white and clear rated for 2.1/2.5/3 Ghz with no rhyme or reason.
david_jr, Home Depot usually has Leviton, from what I've seen, which are blue inserts, rated to 2.5 Ghz, and they work fine in my testing of my H/J set-up - obviously, your mileage may vary. Lowes seems to carry OnQ/Legrand, which are white/clear, but say 3 Ghz on the packaging. My 1 year old bldg used Pass & Seymour (also Legrand) wall plates with white/clear inserts (different from the Lowes ones), and so far, they work just fine with H/J, as well, so who knows.