Copper Grates should filter sky light, just like leaves

There are currently very few blocks in the game that reduce sky light passing through them. This these blocks allow interesting control over light shading, like creating a skylight that provides only little light, or making dimly lit dungeons with small openings to the sky, that barely light up the bottom.
Currently, there are 4 main block types: water, ice, leaves, cobwebs. While there are some others, they aren't well suited to decorating.

So I propose that copper grates should be one of these blocks, I believe it fits their block concept, and would allow using them in more creative ways.