Changing Symbols ...
Each data set has a default plotting symbol (point type, line type, color, and size). However, users can change these values. For example, land color by default is yellow. If you would like to change the color, you would double click on the Land item in the "Data sets to plot" list. This will open a small window allowing you to select a color from the list. For this example, if you choose the third item which is color, and select green, and then press the "commit changes" button, the land color from that moment on will be green.

Similarly, symbol sizes, colors, types, and line types for most data sets can all be changed at the users' will. This gives users a chance to design their own map with the colors and symbols they like to use. User data symbols can also be changed in this way.