I am building a cab booking application, and I need to differentiate the various cabs in the vicinity by their age. Age in the sense how long back did they update their current location. If they update their location frequently enough, I need a good green color. But if they dont update for a while, then I need the customer to know that this cab is kind old, and gradually take this cab out of the list.
I have tried color combinations of green (good), yellow (not updated for 5 mins), grey (not updated for 2 hours). But the more I think of it the more I need the age to be subtle, and not so drastic in its colors.
I need shades of green to just pass on the message without giving the feeling of "oh my god, so many old cabs on the system". I hope I am clear. I need help to decide what shades of green can I use for this purpose. I have thought of these color shades
339900 66FF00 66CC00 33FF66