I meant to say, it's easy to see that you need to put the wall blocks in the two holes. However, it doesn't matter what hole they are put in. I think you can extend this concept, but with more wall blocks and only one possible configuration of wall blocks.
You can't really fail this level (unless you do the obvious purple block in the hole move) I think you can use the trick so that in some combinations, the purple block does get coloured.
You can't really fail this level (unless you do the obvious purple block in the hole move) I think you can use the trick so that in some combinations, the purple block does get coloured.