On Windows, I've noticed that the copernic desktop search system tray icon, which is usually yellow and orange , sometimes turns blue .  It will remain this colour until an update to the index begins, but I haven't been able to determine what causes the change in colour.

Google came up with nothing on this topic, I found no mention of why this might happen in the help files for copernic and so I sent a mail to their support.  A prompt response was received to the effect that it's a "known problem for which there is no solution at the moment" and that they can't tell me "whether this problem will be fixed or not because the list of enhancements or bug fixes to be included hasn't been defined yet".

I posted this entry simply to give google something sensible to return for a search for something like "copernic blue icon".  Hope it answered your question.