Brief summary of issue / Description of requested feature:

There are occasional cases of a white map symbol being hard to read on a light colored background, and likely vice versa with black map symbols. Seen here with white symbols:
https://i.imgur.com/b6bxHCm.png

The formula used to determine what color to use has some clear flaws. Allowing us to choose may alleviate this.

Steps to reproduce the issue / Reasons for adding feature:

1. Quality of life for maps with a lot of variations in room environment colors

Error output / Expected result of feature

Extra information, such as Mudlet version, operating system and ideas for how to solve / implement: