Soraka's Variable Mana Cost Suffers from a Lack of Readability

So I was playing Soraka earlier tonight and I had a lot of trouble because I was constantly trying to cast Infuse on enemies while I did not have the 50 mana open. However, I'm not looking at my mana bar every 2 seconds, I AM looking at my icons to see whether they are grayed out or not. Soraka's Infuse is constantly lit as long as it's off cooldown because the ally cast costs 0 mana, but that throws off a player who is trying to use it offensively without the necessary resources.

Riot has consistently stated their intent to continue to help players with visibility because they are gamers and they understand that not everyone can pay attention to every single detail of the HUD at one time. You guys gave us great changes like the Mordekaiser shield bar, but this is something that is just...awkward. It feels like I'm wasting my time trying to use skills that the game is telling me I can use, but that I am unable to use, when I should be focusing on other things like healing or item actives.

So is there a way we can go around this? The easiest way I can think of would be to make Infuse's ally cast cost the same as her enemy cast but I'm sure I'll get attacked for even mentioning something like that, so there's got to be some other way we can get some consistent clarity.