tar,
It needs to go see the icon doctor......
This sometimes happens when your monitor is set to other than 256 color standard. Try changing the color setting in the monitor if it really bothers you. I have my W98 showing a greyish color while my XP is true blue.
As long as all the functions appear normal, than it is not a concern for worry.
Disable the Resident Protection and see if an x appears across the icon. This would indicate that you have stopped the Resident Protection, but more than that, indicates that things are as they should be.
Enjoy Avast.