There is a ton of visual noise in this game. One of the main problems is with the AOE indicators. ANet seems to want them to all have a shared colour theme to make the fights more clear, but all we're left with is orange circles all over the place, and we're never sure of what's going to hit us... We just know something is going to hit us.
Some AOE show us when they are going to hit, with an inner circle growing inside the indicator. This is a great mechanic, but currently some AOE only have a static indicator that doesn't show when the AOE will strike. The solar blooms in the Chaos fractal, the sandbinders' eruptions in the oasis fractal, the tentacle swipes... It would be nice if there was a wind-up indicator for all of them, no matter how fast they come.
Also, that wind-up indicator should be on all AOE shapes, not just circle and square ones.
That would leave only the persisting AOE without indicator, which would make them more clear and would make more sense in general.
Instead of having orange circles for almost all AOE, with sometime red circles but we're not sure what's the difference is, we should have different indicators depending on the type of AOE it will be. So, here are my suggestions:
Separate crowd control indicators from damage indicators.
If the AOE is a crowd control, put a special mark all around it, on the inner edge of the indicator, to show what kind of AOE it will be.