Credit: I learned this part from a Youtube video of André Biedermann which uses GMapTool and TYPViewer to extract, change, and merge TYP files. On this page I only made the bare minimum of screenshots to help you along. For a more detailled overview I recommend you watch his video. He talks German, but his video is so clear it should be easy to follow nonetheless.
I am using a free map of Cyprus from OpenTopoMap for this tutorial
Open TYPViewer, then select File and open your TYP file
Your TYP file will now open, click on the button “Text / Icons”
In the box “List of Polygons” you can change the colors of different parts of the land, for example how forests appear
All colors are listed by their Hex number (just like the numbers on your color picture). If you use those numbers, the colors will always look the same. There’s options to define colors for night and day separately. Go creative.
Under “List of Polylines” you can change the way roads are displayed
Try out the Line Width and Border Width options
Under “List of POIs” you can change the way POIs (points of interest) such as restaurants appear