You can change the mode with the button that says something like "Mode: auto" or by pressing F10 once or twice.
Making the tileset change color is much trickier, but technically possible with advanced scripting techniques - if you make multiple versions of the same room with different colors, there's the internal scripting command `gotoroom(x,y)` which you could run on some kind of timer. But it requires quite some explanation and layers of background knowledge; how much do you know about (internal) scripting?