I turned Vibrant Visuals on, but other than making the water a bit clearer it doesn’t really seem to do anything, compared to the examples I saw at Minecraft Live and other videos with people using Vibrant Visuals. There are no block or player shadows (see the demonstration cow pen I built, it doesn’t cast a shadow), the sunset/sunrise isn’t any different from normal Minecraft, the clouds still look the same, and there are no “sun ripples” on blocks that are underwater.
Please refer to the changelogs for the list of currently supported processors. If your processor is not listed then it is not currently supported and issues related to that are Invalid.