I'm now on 1.12.2 testing with IIE and I found out that copying the /give command (if you hold down shift and clicked the "Drop" button), the /give command would look something like this:
/give @p minecraft:grass 1 0 1xtile.grass@0
I thought this was some new additions to commands in IIE, but when i executed it, it errors out.

I did this to see how to /give items with a colored name, but now I just have to wait...

Sorry I did not get back to you before now. I added a feature that lets you get the command of an item in your inventory by pressing Ctrl + C while hovering that item. This command should work correctly.
I will fix the other command to work as well.
Thank you for reporting.