Well, that doesn't surprise me either, because many people I have spoken to were also in the dark about this change in gamesplay. Bottom line is.... runes no longer work with white spells.
Yep, now like me I am sure that many people reading this will have spent a lot of time in building up and training the likes of Sage and Tarand in previous seasonal events, and will have added Legendary and Mythical runes that they earned in those dragons' evolutionary branches to them to help boost their powers. On top of this, further ga,esplay and perhaps financial input will have been expended in gathering huge quantities of rune dust to further improve and boost the affects of those runes on the dragons. The reality unfortunately is, at the moment, that all of that has been wasted, as PG have removed the affect of any runes on white spells, like Explosive Shield. A bit of a game changer I think, and one that leaves a very sour taste in the mouth. The reason for this? To balance gameplay apparently. What was so wrong with it?
Now I have spoken to the support lines at PG about this and they have hinted that there may indeed be some recompense for these changes later in the season, with new more specific runes being awarded by players affect by the changes. But there are no firm details about what these might be, or when they might happen.
So my advice to you, would be careful what runes you add to enhance white spells, and take the time to write to PG and ask or complain about these changes. The more of us that complain, the more likely it is that some kind of recompense will be forthcoming.
It is little things like this that are slowly souring the game for many. But play on we will. After all, most of us have invested a lot of hours and money in this game so far and we are not about to walk away just yet. Not with so many bases still to burn.