How to change Mac OS X iCal's calendar color for Microsoft Exchange server account?

I think this issue is specific to Lion. You can't even get to the info screen for an Exchange calendar, to make the colour choice shown in the screen shots here. Googling, I turned up the following Applescript to accomplish the task:

tell application "iCal"
  set color of calendar "Calendar" to choose color default color {0, 0, 0}
end tell

I'm running Snow Leopard and my iCal Get Info command allows me to change colors. Here's a screen capture where I can make this change.

To reach this window, I highlight the exchange "Calendar" in the left hand sidebar of iCal and enter Cmd I.

In my iCal setup, I have "Home" (orange) "Gmail" (blue)and "Exchange" (red). I can get info and change the color for any of the three calendars. In my list, I have "Home", "Gmail" and "Exchange". Here is how 2 appts look:

What do you see when you get info on your exchange account?

After the recent Lion update, the color issue is resolved by right clicking on the desired exchange calendar, and selecting Get Info. A color combo box is now available. Prior to the update, only iCloud or local Calendars would allow color change in Lion.