Allegedly, on or about 29 January 2016, Dennis Jacobfeuerborn sent:
Now I only need to figure out what exactly "di=01;34" vs. "di=38;5;33" means...
Ah, now found a reference for the latter
38;5;33
The 38 prefix apparently means to set the foreground colour, but a 48 prefix apparently means to set the background colour.
No idea how they're using the 5.
The 33 is a colour, but I don't know how that's defined.
Apparently, it's to do with xterm, so you might look into that.