Finally, I also take the "Retro-Pixel Castles"-train departing from the SixtyGig-station.
You probably already thought of this and/or it's most likely a thing to look at in later stages of the development. Either way, whilst fiddling around with the map editor, I somehow had to think of design software such as Photoshop etc. Now, in programs like these there often is a feature that allows you to reduce or enlarge the size of the brush you're using with a combination of keys (like ALT + mousewheel up or down). Something like that would be a convenient thing to have in the final game I thought.
Like I said, you probably already thought of this since you implemented a feature that allows you to activate the "accent mode" via pressing the CTRL key.
Anyways, keep up the good work, it looks great so far!