One of Jasmin Editor key features is syntax highlighting. You can change font style and color for each syntax part using Preferences page.
To open Preferences page open Window -> Preferences dialog. Then select Jaslipse Preferences
Here, by checking and unchecking boxes you can set how each syntax part will be highlighted. You can also change color of the font
Every change you make will be visible in textbox with sample code example below preferences form
To apply your changes simply click on Apply button and exit dialog. Your changes will be used in every newly opened *.j file.