>>18252079>>18252006>>18251965>>18251059>>18251679>>18250493>>18250517>>18250557>>18249496I mentioned this in skype but I'll say it here as well: If you look at screenshots of caves in platinium, at least the blue/purple ones, part of the color is from an overlay or filter, you can tell because the overworld sprite for the player is tinged bluish purple as well.
So the color isn't entirely just from the color of the cave tiles itself. I'm assuming it's similar to how the time of day lighting works, where at night everything outside is darker and a a little bit purple.
