Currently, explored areas turn gray when you are not actively looking at them, but unexplored areas are pitch black. This can create a confusing mix of visible tiles and black tiles depending on the line of sight. Instead of pitch black unexplored tiles, I propose, at the very least, unexplored tiles could have a grid pattern. The grid could be as large as the current tiles, or smaller to set it off further.
I would hope a grid pattern in unexplored tiles would make such tiles less jarring. Currently, the blackness feels very inexplicable given the lovely hand painted graphics. Alternatively, maybe a cloudy black to gray effect is called for. Something to either imply fog, or which leans to the unknown depths and fears of the people who cannot observe those unobserved tiles.