I think the green color means "unvisited" or "unread" so if you viewed the downloads in the Library dialog (Ctrl+j), it would make sense to gray it out.

Oh wait, it already does that. See next post for correction.

Are you using the extension which creates a different downloads window? You may need to contact the extension author about adding this feature to the extension.

My mistake, if you already have the Library dialog open, then simply switching over to it and interacting with it (I just deleted the one recent download) doesn't turn off the green arrow. This could be a new bug if you'd like to file one.

https://bugzilla.mozilla.org/

No, I'm not using another extension that has a download window. I'm using the default download manager.

When you press Ctrl+J or use the arrow to open the download manager it turns the arrow black. I'm referring to when you leave the download manager open.

If you leave the download manager open as you add more files the arrow will turn green signaling finished downloads. Since the download manager is open, if you select "Clear Downloads" your download list is cleared. The arrow however stays green. If you cleared all downloads, the arrow staying green makes no sense. There are no more downloads.

Sorry, I posted as you were posting your second response. I was hoping there was a solution in about:config, but I guess not.

I'll file a bug after searching if it wasn't already reported. Thank you for directing me to Bugzilla.