How to use a id that has a data value assigned to it?

[whatwhyletmeconnect]

Sorry if this was explained somewhere! Just cant figure out

[TheBeems]

As stated in the help command:

"fill", "Fills an area with blocks.", "First place two marks on the map, then type 'fill' to fill it with the standard building block.\nOr use 'fill <blockid> <blockdata>' to specify the block to fill with."],

You can only pass a number as an argument to a function (functions like fill). So when you want to use a blockid and a blockdata, you have to pass them separately instead of using the colon per your example. So fill 251 15 for Black Concrete.