I’m not 100% sure I understand what you’re looking for : The Colorize device is under “Converter”, but you mention that this isn’t what you want…
Macros are allowed to exist only within a given file. If you have a file with a Colorize macro, you can save it to your library for safekeeping however, by selecting it and then selecting “Save device to library” from the Device Commands menu. It will then be available for you in other projects.
Ok I’ve got a pic here that shows the difference between the colorizer & the Colorize nodes.
The colorizer node that you can pick from the menu, only allows you to use the current world colors. or use the built in color tables (greyscale woodlands etc)…
But…
The colorize node from inside the Costal Overlay macro, allows you to pick 2 colors without pointing to the world colors or the built in methods.