Very Translucent Grass Blocks

In superflat worlds (I don't know if this happens on normal worlds) with user interface opacity on 50%, when my hotbar turns translucent, the other items do as well, but the grass blocks turn completely invisible, but they are still there, I tried it in the normal texture pack and the Fallout texture pack.

To replicate hold a grass block, then turn your interface opacity to 30, wait for your interface to get transparent, and you'll see that, even while holding the grass block, it appears tottaly transparent (invisible) in your hotbar.

Update: Since the latest update grass isn't completely transparent like before, but it's transparency is still much more intense that the other items in the hotbar.

(sorry about the images being upside down, I don't know why this always happens)