Hi,
Thanks for the suggestion, yes it's a good idea and I'm fairly sure it's something that has been on the "todo (maybe)" list for some time.
CharPad includes the maps from 'Hawkeye' and 'Flimbo's Quest' which both use colour switching in their actual games and so don't appear quite correct in CharPad.
(The lowest tile rows for those games are dynamically recoloured using a raster IRQ/colour split)
As it may (sooner or later) be desirable for a "split" to occur on any raster line (ie. mid-tile or mid-char) then I would probably rule out doing it in the map editor or per-char/tile and instead have something like a "Screen Emulator" window that could be configured with the desired splits/colours on the chosen raster lines.
The more I think about it, the more I think it's something that would be far simpler to do using some native C64 code and ie. the VICE emulator.
I know ideally you would want it to be immediately visible IN the map editor but I can't see that happening to be honest.
CharPad's map editor/renderer is not really "line based", is fully resizable and does not actually represent a "screen".
I will consider it further!