This must have been asked thousands of times because it is so obvious, yet
everyuting I can find about it is so cryptic as to be useless.

How in docbook (generating PDF) can I get coloured text? Colour is clearly
available as admonitions and table borders can be coloured, but I have found
no way to make an arbitrary phrase a different colour from the surrounding
text.

I am using Oxygen + Saxon 5.3.