Color of map areas you've been to in a session.

I really like that there is a slight color change of map areas you’ve been to in a session - but it would be very helpful to be able to change or amplify that color so that it may be more noticeable, should the player want. For myself, the color is subtle, but too subtle that sometimes I have to really examine if the hue is that of a place I’ve been, or haven’t been in this session.

+1. I think the map is such an important part of the UI and there are almost no customization options for it. I also would like to have the explored areas be shared amongst characters and difficulty levels, maybe 3 layers instead of 2.
First layer: Has any of your characters ever been here ?
Second layer: Has this character ever been here in this difficulty ?
Third layer: Has this character, in this difficulty ever been here in this play session ?

I really hate to lose all my map progress, i know the map already, why does my new char have to explore it all over again.

I never had this problem before, its greyscale when you have been before in a previous session and it gets colored if you visit the place again
I cant say much of it tho since im playing this on pc monitor and im near the screen but i suppose if you play on a bigger far away screen might be an issue