Well, you could implement your own console for output (using a Frame and whatever windowing widgets you want) and set the text to whatever color/font/size you like. This is not as hard as it sounds.

However, escape sequences are not very portable. For example, Windows NT provides an ANSI.SYS driver, but only for legacy DOS applications (which a JVM is not). I do not recommend this option except ...

Java SE 13 (Sept 2019) introduced text blocks as a preview feature, aimed at reducing the pain of declaring and using multi-line string literals in Java. It was subsequently refined in a second ...