Ooh, I like this idea! They would just slightly brighten other surrounding blocks, but their colors would still glow beautifully in the dark. I want this to be a thing now!
We have cocoa beans. It would be pretty neat if we could have chocolate cake.
Yes, It would be great if comparators could detect that something is in the cart.
Activate redstone next to a Hopper; this should stop items from getting in and out.