Tinted Echo Glass

Until/if we ever get a way to pacify hostile mobs with an item/setting, it would be nice to have them standing around in set locations in our realms. But instead of having visible blocks/tinted glass around/above the mobs that can burn, would be nice if there was a way to make it where echo glass could block out light/the sun? or have a tinted glass version.

Could put them in water, but they those some height then.