Moving Duplicants

If you were to direct your Duplicant into a territory in which it isn't able to venture to, the mark/signal of the placement stays on the block that you directed your Duplicant to. The only way to get rid of the red mark on your screen is to go back to the option to move your Duplicant... and move them to a place they can walk to. This isn't that big of a deal, but it'd be nice to cancel the option to mark a block that a Duplicant cannot seem to get to.