Download the Crimson Editor program from
Download any optional syntax coloring files needed (i.e. MIPS/SPIM) from the syntax file link on the Crimson editor web page. Some versions of Crimson editor are setup to color *.mips files for SPIM and not *.s files. They are using *.s for another file type.
Unzip the syntax files and move the link.* file to the crimson editor link directory and the two files, *.key and *.spc to the crimson editor spec directory. The default location for these directories is C: /Program Files/Crimson Editor.
Start up the editor and open an example file. The standard file extension automatically selects the proper syntax coloring files. Syntax coloring should now be working.