I was following alphadog's tutorial, and after completing step six, this happened.
As you can see, the locked door to the north is a different color than the rest of the dungeon.
I tried removing the door, replacing the door, using F7 for the whole room and all layers. I need help.
You need to edit the Cset for the door template :P IIRC, it should be under Edit > Doors, and you can change the doors Cset (By technically replacing the combos). It's currently Cset2.
But what I really really suggest is that you use a different pallete for dungeons. (IIRC, that's supposed to be pallete 3, in AlphaDawg's tutorial.)
I believe you're using the wrong palette. Press the number 3 on your keyboard to switch to level 3's palette (as it says in the tutorial).