When playing some game in the PBE recently I have noticed that the Icons for Smite and Cassiopeia's abilities are blue instead of their normal picture. it has no affect on gameplay though.

I'm not sure if this is a server problem or your computer problem since the icons seems to be find for me and that your computer can have corrupt file of the pictures so that you would see a blue icon in the place of the ability icons.
So in short, try to repair the game and see what happens.